{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-42055", "assignerOrgId": "9dacffd4-cb11-413f-8451-fbbfd4ddc0ab", "state": "PUBLISHED", "assignerShortName": "f5", "dateReserved": "2026-06-02T21:45:04.818Z", "datePublished": "2026-06-17T14:04:32.520Z", "dateUpdated": "2026-07-15T00:58:16.251Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unknown", "modules": ["ngx_http_proxy_v2_module", "ngx_http_grpc_module"], "product": "NGINX Open Source", "vendor": "F5", "versions": [{"lessThan": "1.31.2", "status": "affected", "version": "1.13.10", "versionType": "custom"}, {"lessThan": "1.30.3", "status": "affected", "version": "1.30.2", "versionType": "custom"}]}, {"defaultStatus": "unaffected", "modules": ["ngx_http_proxy_v2_module", "ngx_http_grpc_module"], "product": "NGINX Plus", "vendor": "F5", "versions": [{"lessThan": "37.0.2.1", "status": "affected", "version": "37.0", "versionType": "custom"}, {"lessThan": "R36 P6", "status": "affected", "version": "R36", "versionType": "custom"}]}], "credits": [{"lang": "en", "type": "reporter", "value": "\"F5 acknowledges Mufeed VH of Winfunc Research, Trung Nguyen (@everping) of CyStack, Feng Xue and XGPT of ThreatBook, Hcamael and \u7ae0\u9c7c\u54e5 of aipyapp, and Zhen Yan (AntAISecurityLab) for bringing this issue to our attention and following the highest standards of coordinated disclosure.\""}], "datePublic": "2026-06-17T14:00:00.000Z", "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<span style=\"background-color: rgb(255, 255, 255);\">NGINX Plus and NGINX Open Source have a vulnerability in the </span><strong>ngx_http_proxy_v2_module</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;and </span><strong>ngx_http_grpc_module</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;modules. This vulnerability exists when the </span><strong>proxy_http_version to 2</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;or </span><strong>grpc_pass</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;directives are used to proxy HTTP/2 traffic, the </span><strong>ignore_invalid_headers</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;directive is set to off, and the </span><strong>large_client_header_buffers</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;directive size is larger than 2 megabytes. A remote, unauthenticated attacker, along with conditions beyond their control, could send large headers while creating an upstream request. This may cause a heap-based buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR.</span> \n\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated."}], "value": "NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_proxy_v2_module\u00a0and ngx_http_grpc_module\u00a0modules. This vulnerability exists when the proxy_http_version to 2\u00a0or grpc_pass\u00a0directives are used to proxy HTTP/2 traffic, the ignore_invalid_headers\u00a0directive is set to off, and the large_client_header_buffers\u00a0directive size is larger than 2 megabytes. A remote, unauthenticated attacker, along with conditions beyond their control, could send large headers while creating an upstream request. This may cause a heap-based buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. \n\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated."}], "metrics": [{"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}, {"cvssV4_0": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "baseScore": 9.2, "baseSeverity": "CRITICAL", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-122", "description": "CWE-122 Heap-based Buffer Overflow", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "9dacffd4-cb11-413f-8451-fbbfd4ddc0ab", "shortName": "f5", "dateUpdated": "2026-06-17T14:04:32.520Z"}, "references": [{"tags": ["vendor-advisory"], "url": "https://my.f5.com/manage/s/article/K000161584"}], "source": {"discovery": "EXTERNAL"}, "tags": ["x_F5"], "title": "NGINX ngx_http_proxy_v2_module and ngx_http_grpc_module vulnerability", "x_generator": {"engine": "F5 SIRTBot v1.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-06-17T00:00:00+00:00", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3", "id": "CVE-2026-42055"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-06-18T03:57:46.697Z"}}, {"affected": [{"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:10.2"], "defaultStatus": "affected", "packageName": "nginx", "product": "Red Hat Enterprise Linux 10", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "2:1.26.3-6.el10_2.5", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:enterprise_linux:8"], "defaultStatus": "affected", "packageName": "nginx:1.24", "product": "Red Hat Enterprise Linux 8", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "8100020260707171317.489197e6", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:enterprise_linux:9"], "defaultStatus": "affected", "packageName": "nginx", "product": "Red Hat Enterprise Linux 9", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "2:1.20.1-28.el9_8.4", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:enterprise_linux:9"], "defaultStatus": "affected", "packageName": "nginx:1.24", "product": "Red Hat Enterprise Linux 9", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "9080020260707164406.9", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:enterprise_linux:9"], "defaultStatus": "affected", "packageName": "nginx:1.26", "product": "Red Hat Enterprise Linux 9", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "9080020260707110000.9", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:hummingbird:1"], "defaultStatus": "affected", "packageName": "nginx-main", "product": "Red Hat Hardened Images", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "1.30.3-2.hum1", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:openshift_data_foundation:4"], "defaultStatus": "unaffected", "packageName": "odf4/ocs-client-console-rhel9", "product": "Red Hat Openshift Data Foundation 4", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:openshift_data_foundation:4"], "defaultStatus": "affected", "packageName": "odf4/odf-console-rhel9", "product": "Red Hat Openshift Data Foundation 4", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:openshift_data_foundation:4"], "defaultStatus": "unaffected", "packageName": "odf4/odf-multicluster-console-rhel9", "product": "Red Hat Openshift Data Foundation 4", "vendor": "Red Hat"}], "datePublic": "2026-06-17T14:04:32.520Z", "descriptions": [{"lang": "en", "value": "A flaw was found in NGINX. When NGINX is configured to proxy HTTP/2 traffic using the ngx_http_proxy_v2_module or ngx_http_grpc_module with specific settings, a remote, unauthenticated attacker can send specially crafted large headers. This can trigger a heap-based buffer overflow, leading to a restart of the NGINX worker process and a Denial of Service (DoS). Under certain conditions, such as when Address Space Layout Randomization (ASLR) is disabled or bypassed, this vulnerability could also allow for arbitrary code execution."}], "metrics": [{"other": {"content": {"namespace": "https://access.redhat.com/security/updates/classification/", "value": "Important"}, "type": "Red Hat severity rating"}}, {"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "format": "CVSS"}], "problemTypes": [{"descriptions": [{"cweId": "CWE-131", "description": "Incorrect Calculation of Buffer Size", "lang": "en", "type": "CWE"}]}], "references": [{"tags": ["vdb-entry", "x_refsource_REDHAT"], "url": "https://access.redhat.com/security/cve/CVE-2026-42055"}, {"name": "RHBZ#2489866", "tags": ["issue-tracking", "x_refsource_REDHAT"], "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2489866"}, {"tags": ["x_sadp-csaf-vex"], "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42055.json"}, {"tags": ["vendor-advisory", "x_refsource_REDHAT"], "url": "https://access.redhat.com/errata/RHSA-2026:36364"}, {"tags": ["vendor-advisory", "x_refsource_REDHAT"], "url": "https://access.redhat.com/errata/RHSA-2026:38847"}, {"tags": ["vendor-advisory", "x_refsource_REDHAT"], "url": "https://access.redhat.com/errata/RHSA-2026:36618"}, {"tags": ["vendor-advisory", "x_refsource_REDHAT"], "url": "https://access.redhat.com/errata/RHSA-2026:36331"}, {"tags": ["vendor-advisory", "x_refsource_REDHAT"], "url": "https://access.redhat.com/errata/RHSA-2026:36639"}, {"tags": ["vendor-advisory", "x_refsource_REDHAT"], "url": "https://access.redhat.com/errata/RHSA-2026:27197"}], "solutions": [{"lang": "en", "value": "RHSA-2026:36364: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)"}, {"lang": "en", "value": "RHSA-2026:38847: Red Hat Enterprise Linux AppStream (v. 8)"}, {"lang": "en", "value": "RHSA-2026:36618: Red Hat Enterprise Linux AppStream (v. 9)"}, {"lang": "en", "value": "RHSA-2026:36331: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)"}, {"lang": "en", "value": "RHSA-2026:36639: Red Hat Enterprise Linux AppStream (v. 9)"}, {"lang": "en", "value": "RHSA-2026:27197: Red Hat Hardened Images"}], "timeline": [{"lang": "en", "time": "2026-06-17T16:01:41.848Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-06-17T14:04:32.520Z", "value": "Made public."}], "title": "nginx: NGINX: Arbitrary code execution or Denial of Service via heap-based buffer overflow with crafted HTTP/2 headers", "workarounds": [{"lang": "en", "value": "To mitigate this vulnerability, ensure that the `ignore_invalid_headers` directive is set to `on` in your NGINX configuration, or reduce the size specified by the `large_client_header_buffers` directive to 2 megabytes or less. These changes require an NGINX service reload or restart to take effect. Reloading the NGINX service is generally safe, but a restart will briefly interrupt service."}], "x_adpType": "supplier", "x_generator": {"engine": "sadp-cli 1.0.0"}, "providerMetadata": {"orgId": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "shortName": "redhat-SADP", "dateUpdated": "2026-07-15T00:58:16.251Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "nginx: NGINX: Arbitrary code execution or Denial of Service via heap-based buffer overflow with crafted HTTP/2 headers", "metrics": [{"other": {"type": "Red Hat severity rating", "content": {"value": "Important", "namespace": "https://access.redhat.com/security/updates/classification/"}}}, {"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.1, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}}], "affected": [{"cpes": ["cpe:/o:redhat:enterprise_linux:10.2"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux AppStream (v. 10)", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:enterprise_linux:8::appstream"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux AppStream (v. 8)", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:enterprise_linux:9::appstream"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux AppStream (v. 9)", "defaultStatus": "affected"}, {"cpes": ["cpe:/o:redhat:enterprise_linux:10.2"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:enterprise_linux:9::crb"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:hummingbird:1"], "vendor": "Red Hat", "product": "Red Hat Hardened Images", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:openshift_data_foundation:4"], "vendor": "Red Hat", "product": "Red Hat Openshift Data Foundation 4", "defaultStatus": "affected"}], "timeline": [{"lang": "en", "time": "2026-06-17T16:01:41.848Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-06-17T14:04:32.520Z", "value": "Made public."}], "solutions": [{"lang": "en", "value": "RHSA-2026:36364: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)"}, {"lang": "en", "value": "RHSA-2026:38847: Red Hat Enterprise Linux AppStream (v. 8)"}, {"lang": "en", "value": "RHSA-2026:36618: Red Hat Enterprise Linux AppStream (v. 9)"}, {"lang": "en", "value": "RHSA-2026:36331: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)"}, {"lang": "en", "value": "RHSA-2026:36639: Red Hat Enterprise Linux AppStream (v. 9)"}, {"lang": "en", "value": "RHSA-2026:27197: Red Hat Hardened Images"}], "x_adpType": "supplier", "datePublic": "2026-06-17T14:04:32.520Z", "references": [{"url": "https://access.redhat.com/security/cve/CVE-2026-42055", "tags": ["vdb-entry", "x_refsource_REDHAT"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2489866", "name": "RHBZ#2489866", "tags": ["issue-tracking", "x_refsource_REDHAT"]}, {"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42055.json", "tags": ["x_sadp-csaf-vex"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:36364", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:38847", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:36618", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:36331", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:36639", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:27197", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}], "workarounds": [{"lang": "en", "value": "To mitigate this vulnerability, ensure that the `ignore_invalid_headers` directive is set to `on` in your NGINX configuration, or reduce the size specified by the `large_client_header_buffers` directive to 2 megabytes or less. These changes require an NGINX service reload or restart to take effect. Reloading the NGINX service is generally safe, but a restart will briefly interrupt service."}], "x_generator": {"engine": "sadp-cli 1.0.0"}, "descriptions": [{"lang": "en", "value": "A flaw was found in NGINX. When NGINX is configured to proxy HTTP/2 traffic using the ngx_http_proxy_v2_module or ngx_http_grpc_module with specific settings, a remote, unauthenticated attacker can send specially crafted large headers. This can trigger a heap-based buffer overflow, leading to a restart of the NGINX worker process and a Denial of Service (DoS). Under certain conditions, such as when Address Space Layout Randomization (ASLR) is disabled or bypassed, this vulnerability could also allow for arbitrary code execution."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-131", "description": "Incorrect Calculation of Buffer Size"}]}], "providerMetadata": {"orgId": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "shortName": "redhat-SADP", "dateUpdated": "2026-07-14T12:04:44.960Z"}}, {"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-42055", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-06-17T15:43:07.643763Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-06-17T15:43:12.416Z"}}], "cna": {"tags": ["x_F5"], "title": "NGINX ngx_http_proxy_v2_module and ngx_http_grpc_module vulnerability", "source": {"discovery": "EXTERNAL"}, "credits": [{"lang": "en", "type": "reporter", "value": "\"F5 acknowledges Mufeed VH of Winfunc Research, Trung Nguyen (@everping) of CyStack, Feng Xue and XGPT of ThreatBook, Hcamael and \u7ae0\u9c7c\u54e5 of aipyapp, and Zhen Yan (AntAISecurityLab) for bringing this issue to our attention and following the highest standards of coordinated disclosure.\""}], "metrics": [{"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.1, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}, {"format": "CVSS", "cvssV4_0": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 9.2, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "affected": [{"vendor": "F5", "modules": ["ngx_http_proxy_v2_module", "ngx_http_grpc_module"], "product": "NGINX Open Source", "versions": [{"status": "affected", "version": "1.13.10", "lessThan": "1.31.2", "versionType": "custom"}, {"status": "affected", "version": "1.30.2", "lessThan": "1.30.3", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "F5", "modules": ["ngx_http_proxy_v2_module", "ngx_http_grpc_module"], "product": "NGINX Plus", "versions": [{"status": "affected", "version": "37.0", "lessThan": "37.0.2.1", "versionType": "custom"}, {"status": "affected", "version": "R36", "lessThan": "R36 P6", "versionType": "custom"}], "defaultStatus": "unaffected"}], "datePublic": "2026-06-17T14:00:00.000Z", "references": [{"url": "https://my.f5.com/manage/s/article/K000161584", "tags": ["vendor-advisory"]}], "x_generator": {"engine": "F5 SIRTBot v1.0"}, "descriptions": [{"lang": "en", "value": "NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_proxy_v2_module\u00a0and ngx_http_grpc_module\u00a0modules. This vulnerability exists when the proxy_http_version to 2\u00a0or grpc_pass\u00a0directives are used to proxy HTTP/2 traffic, the ignore_invalid_headers\u00a0directive is set to off, and the large_client_header_buffers\u00a0directive size is larger than 2 megabytes. A remote, unauthenticated attacker, along with conditions beyond their control, could send large headers while creating an upstream request. This may cause a heap-based buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. \n\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated.", "supportingMedia": [{"type": "text/html", "value": "<span style=\"background-color: rgb(255, 255, 255);\">NGINX Plus and NGINX Open Source have a vulnerability in the </span><strong>ngx_http_proxy_v2_module</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;and </span><strong>ngx_http_grpc_module</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;modules. This vulnerability exists when the </span><strong>proxy_http_version to 2</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;or </span><strong>grpc_pass</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;directives are used to proxy HTTP/2 traffic, the </span><strong>ignore_invalid_headers</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;directive is set to off, and the </span><strong>large_client_header_buffers</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;directive size is larger than 2 megabytes. A remote, unauthenticated attacker, along with conditions beyond their control, could send large headers while creating an upstream request. This may cause a heap-based buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR.</span> \n\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated.", "base64": false}]}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-122", "description": "CWE-122 Heap-based Buffer Overflow"}]}], "providerMetadata": {"orgId": "9dacffd4-cb11-413f-8451-fbbfd4ddc0ab", "shortName": "f5", "dateUpdated": "2026-06-17T14:04:32.520Z"}}}, "cveMetadata": {"cveId": "CVE-2026-42055", "state": "PUBLISHED", "dateUpdated": "2026-07-14T12:04:44.960Z", "dateReserved": "2026-06-02T21:45:04.818Z", "assignerOrgId": "9dacffd4-cb11-413f-8451-fbbfd4ddc0ab", "datePublished": "2026-06-17T14:04:32.520Z", "assignerShortName": "f5"}, "dataVersion": "5.2"}

{}

{"bugzilla": {"description": "nginx: NGINX: Arbitrary code execution or Denial of Service via heap-based buffer overflow with crafted HTTP/2 headers", "id": "2489866", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2489866"}, "csaw": false, "cvss3": {"cvss3_base_score": "8.1", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-131", "details": ["A flaw was found in NGINX. When NGINX is configured to proxy HTTP/2 traffic using the ngx_http_proxy_v2_module or ngx_http_grpc_module with specific settings, a remote, unauthenticated attacker can send specially crafted large headers. This can trigger a heap-based buffer overflow, leading to a restart of the NGINX worker process and a Denial of Service (DoS). Under certain conditions, such as when Address Space Layout Randomization (ASLR) is disabled or bypassed, this vulnerability could also allow for arbitrary code execution."], "mitigation": {"lang": "en:us", "value": "To mitigate this vulnerability, ensure that the `ignore_invalid_headers` directive is set to `on` in your NGINX configuration, or reduce the size specified by the `large_client_header_buffers` directive to 2 megabytes or less. These changes require an NGINX service reload or restart to take effect. Reloading the NGINX service is generally safe, but a restart will briefly interrupt service."}, "name": "CVE-2026-42055", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "nginx", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "nginx", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "nginx", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "nginx:1.24/nginx", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "nginx:1.26/nginx", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Affected", "package_name": "nginx", "product_name": "Red Hat Hardened Images"}], "public_date": "2026-06-17T14:04:32Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-42055\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-42055\nhttps://my.f5.com/manage/s/article/K000161584"], "statement": "This issue is classified as Important severity primarily because:\nConditions for Exploitation: A remote, unauthenticated attacker can only exploit this if NGINX is explicitly configured to proxy HTTP/2 traffic using the ngx_http_proxy_v2_module or ngx_http_grpc_module.\nImpact Limitations: While the flaw reliably causes a Denial of Service (worker restart), achieving arbitrary code execution is highly complex in modern environments as it requires the attacker to bypass or disable Address Space Layout Randomization (ASLR)", "threat_severity": "Important"}