{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-53586", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-06-09T19:11:53.484Z", "datePublished": "2026-08-20T18:40:08.673Z", "dateUpdated": "2026-08-21T21:46:05.425Z"}, "containers": {"cna": {"title": "libgit2: HTTP transport can leak credentials to an offsite redirect target", "problemTypes": [{"descriptions": [{"cweId": "CWE-200", "lang": "en", "description": "CWE-200: Exposure of Sensitive Information to an Unauthorized Actor", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-522", "lang": "en", "description": "CWE-522: Insufficiently Protected Credentials", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-601", "lang": "en", "description": "CWE-601: URL Redirection to Untrusted Site ('Open Redirect')", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N", "version": "3.1"}}], "references": [{"name": "https://github.com/libgit2/libgit2/security/advisories/GHSA-2889-x8f6-mc4x", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/libgit2/libgit2/security/advisories/GHSA-2889-x8f6-mc4x"}, {"name": "https://github.com/libgit2/libgit2/commit/07de6a7e438f95ac9a6efd3222a82117e871ed27", "tags": ["x_refsource_MISC"], "url": "https://github.com/libgit2/libgit2/commit/07de6a7e438f95ac9a6efd3222a82117e871ed27"}, {"name": "https://github.com/libgit2/libgit2/commit/af2b29ad0a74d5bac9751376879ddaf848136d3b", "tags": ["x_refsource_MISC"], "url": "https://github.com/libgit2/libgit2/commit/af2b29ad0a74d5bac9751376879ddaf848136d3b"}, {"name": "https://github.com/libgit2/libgit2/commit/c1507abc44647b3acd832a33a5b1c8c9f5ba8821", "tags": ["x_refsource_MISC"], "url": "https://github.com/libgit2/libgit2/commit/c1507abc44647b3acd832a33a5b1c8c9f5ba8821"}, {"name": "https://github.com/libgit2/libgit2/releases/tag/v1.8.6", "tags": ["x_refsource_MISC"], "url": "https://github.com/libgit2/libgit2/releases/tag/v1.8.6"}, {"name": "https://github.com/libgit2/libgit2/releases/tag/v1.9.5", "tags": ["x_refsource_MISC"], "url": "https://github.com/libgit2/libgit2/releases/tag/v1.9.5"}], "affected": [{"vendor": "libgit2", "product": "libgit2", "versions": [{"version": "< 1.8.6", "status": "affected"}, {"version": ">= 1.9.0, < 1.9.5", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-08-20T18:40:08.673Z"}, "descriptions": [{"lang": "en", "value": "libgit2 is a portable C implementation of the Git core methods provided as a linkable library with a solid API, allowing to build Git functionality into your application. Prior to 1.8.6 and 1.9.5, the built-in HTTP transport in src/libgit2/transports/http.c follows an offsite initial redirect, and handle_remote_auth and handle_auth pass transport->owner->url instead of transport->server.url to the credential callback when the redirected host returns 401 Unauthorized. A callback that scopes credentials to the original trusted URL can therefore return GIT_CREDENTIAL_USERPASS_PLAINTEXT credentials that libgit2 stores in transport->server.cred and sends as an Authorization header to the redirected host. An attacker who controls a trusted Git host or an open redirect on that host can disclose HTTP Basic credentials, personal access tokens, or equivalent credentials. This issue is fixed in versions 1.8.6 and 1.9.5."}], "source": {"advisory": "GHSA-2889-x8f6-mc4x", "discovery": "UNKNOWN"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-08-21T20:58:39.443105Z", "id": "CVE-2026-53586", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-21T21:46:05.425Z"}}]}}

{}

{"affected": [{"affectedData": [{"product": "libgit2", "vendor": "libgit2", "versions": [{"status": "affected", "version": "< 1.8.6"}, {"status": "affected", "version": ">= 1.9.0, < 1.9.5"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "libgit2 is a portable C implementation of the Git core methods provided as a linkable library with a solid API, allowing to build Git functionality into your application. Prior to 1.8.6 and 1.9.5, the built-in HTTP transport in src/libgit2/transports/http.c follows an offsite initial redirect, and handle_remote_auth and handle_auth pass transport->owner->url instead of transport->server.url to the credential callback when the redirected host returns 401 Unauthorized. A callback that scopes credentials to the original trusted URL can therefore return GIT_CREDENTIAL_USERPASS_PLAINTEXT credentials that libgit2 stores in transport->server.cred and sends as an Authorization header to the redirected host. An attacker who controls a trusted Git host or an open redirect on that host can disclose HTTP Basic credentials, personal access tokens, or equivalent credentials. This issue is fixed in versions 1.8.6 and 1.9.5."}], "id": "CVE-2026-53586", "lastModified": "2026-08-21T22:16:39.980", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 3.6, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-53586", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-08-21T20:58:39.443105Z", "version": "2.0.3"}}]}, "published": "2026-08-20T19:16:54.983", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/libgit2/libgit2/commit/07de6a7e438f95ac9a6efd3222a82117e871ed27"}, {"source": "security-advisories@github.com", "url": "https://github.com/libgit2/libgit2/commit/af2b29ad0a74d5bac9751376879ddaf848136d3b"}, {"source": "security-advisories@github.com", "url": "https://github.com/libgit2/libgit2/commit/c1507abc44647b3acd832a33a5b1c8c9f5ba8821"}, {"source": "security-advisories@github.com", "url": "https://github.com/libgit2/libgit2/releases/tag/v1.8.6"}, {"source": "security-advisories@github.com", "url": "https://github.com/libgit2/libgit2/releases/tag/v1.9.5"}, {"source": "security-advisories@github.com", "url": "https://github.com/libgit2/libgit2/security/advisories/GHSA-2889-x8f6-mc4x"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-200"}, {"lang": "en", "value": "CWE-522"}, {"lang": "en", "value": "CWE-601"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{"bugzilla": {"description": "libgit2: libgit2: Information disclosure via HTTP redirect allows credential leakage", "id": "2520691", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2520691"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N", "status": "draft"}, "cwe": "CWE-201", "details": ["libgit2 is a portable C implementation of the Git core methods provided as a linkable library with a solid API, allowing to build Git functionality into your application. Prior to 1.8.6 and 1.9.5, the built-in HTTP transport in src/libgit2/transports/http.c follows an offsite initial redirect, and handle_remote_auth and handle_auth pass transport->owner->url instead of transport->server.url to the credential callback when the redirected host returns 401 Unauthorized. A callback that scopes credentials to the original trusted URL can therefore return GIT_CREDENTIAL_USERPASS_PLAINTEXT credentials that libgit2 stores in transport->server.cred and sends as an Authorization header to the redirected host. An attacker who controls a trusted Git host or an open redirect on that host can disclose HTTP Basic credentials, personal access tokens, or equivalent credentials. This issue is fixed in versions 1.8.6 and 1.9.5.", "A flaw was found in libgit2. The built-in HTTP transport component incorrectly handles offsite redirects, leading to the disclosure of sensitive information. An attacker controlling a trusted Git host or an open redirect on that host could exploit this by causing the library to send HTTP Basic credentials or personal access tokens to an unintended third-party server. This vulnerability results in the leakage of user authentication credentials."], "mitigation": {"lang": "en:us", "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability."}, "name": "CVE-2026-53586", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "rust", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "libgit2", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "rust", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Fix deferred", "package_name": "libgit2", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Fix deferred", "package_name": "rust", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Affected", "package_name": "libgit2", "product_name": "Red Hat Hardened Images"}], "public_date": "2026-08-20T18:40:08Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-53586\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-53586\nhttps://github.com/libgit2/libgit2/commit/07de6a7e438f95ac9a6efd3222a82117e871ed27\nhttps://github.com/libgit2/libgit2/commit/af2b29ad0a74d5bac9751376879ddaf848136d3b\nhttps://github.com/libgit2/libgit2/commit/c1507abc44647b3acd832a33a5b1c8c9f5ba8821\nhttps://github.com/libgit2/libgit2/releases/tag/v1.8.6\nhttps://github.com/libgit2/libgit2/releases/tag/v1.9.5\nhttps://github.com/libgit2/libgit2/security/advisories/GHSA-2889-x8f6-mc4x"], "threat_severity": "Moderate"}