{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-80545", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.765Z", "datePublished": "2026-08-26T14:37:16.956Z", "dateUpdated": "2026-08-27T05:01:32.688Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-27T05:01:32.688Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/zcrypt: Improve EP11 CPRB length and overflow checks\n\nThe xcrb_msg_to_type6_ep11cprb_msgx() function lacks proper input\nvalidation, creating security vulnerabilities:\n1. Missing minimum size validation: The ep11_cprb structure and\n subsequent payload fields (pld_tag, pld_lenfmt) are copied from\n userspace without verifying sufficient buffer length.\n2. Arithmetic overflow in length calculations: CEIL4 alignment could\n overflow, bypassing size checks and enabling buffer overflows.\n3. The payload is asn1 encoded but the function just uses a simple c\n struct overlay to access some fields of the payload.\n\nFix by using size_t for length calculations, adding U32_MAX boundary\nchecks after alignment, and validating minimum request size and\nminimum reply size before copying from userspace. Do a very simple\nasn1 parsing of the payload up to the function value field."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The flaw is reached only via local ioctl(ZSENDEP11CPRB) on /dev/z90crypt or administrator-created zcdn device nodes on IBM Z systems with EP11 crypto hardware; there is no network, Bluetooth, or USB packet path to this code.\nAC:L - The attacker fully controls ep11_urb req_len, req, and resp_len in the ioctl argument; near-SIZE_MAX lengths can wrap CEIL4 sum checks to bypass bufsize validation and trigger deterministic heap corruption without races or external timing dependencies.\nPR:L - Exploitation requires opening a zcrypt device and passing zcrypt_check_ioctl, access routinely delegated to non-root application/service accounts via zcdn nodes on shared IBM Z cloud, LPAR, and container deployments that grant EP11 CPRB ioctl permissions.\nUI:N - Triggering is self-contained by submitting a crafted EP11 request block through ioctl; no victim interaction, file opening by another user, or administrative action beyond having zcrypt device access is required.\nS:U - Impact is kernel heap corruption and privilege escalation within the same Linux security authority on the s390 host; it does not cross VM, IOMMU, or container sandbox boundaries to affect a separate security domain.\nC:H - Undersized copies leave uninitialized kmalloc data readable via struct overlays on pld_lenfmt and payload_hdr, while integer-overflowed req_len values enable copy_from_user far beyond the ap_msg buffer, providing arbitrary kernel memory disclosure primitives.\nI:H - Missing minimum-size and U32_MAX boundary checks let attacker-controlled lengths bypass ap_msg->len validation and corrupt adjacent kmalloc objects in the crypto message buffer, enabling heap control primitives and potential arbitrary kernel code execution.\nA:H - Heap buffer overflow and out-of-bounds parsing of EP11 CPRB payloads can cause kernel oops, panic, or denial of crypto services on mission-critical IBM Z systems; memory corruption alone threatens host availability even before full exploitation."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/s390/crypto/zcrypt_msgtype6.c"], "versions": [{"version": "e2c6d91eb8b1533753755f07803e47eceed263d0", "lessThan": "2976b9d2e716c7e5487ca7c29a7bd076cf9adf08", "status": "affected", "versionType": "git"}, {"version": "e2c6d91eb8b1533753755f07803e47eceed263d0", "lessThan": "17ac0bc866fc624cd05f022dcd8b730c0af11bb1", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/s390/crypto/zcrypt_msgtype6.c"], "versions": [{"version": "7.1", "status": "affected"}, {"version": "0", "lessThan": "7.1", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.10", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.1", "versionEndExcluding": "7.1.10"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.1", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/2976b9d2e716c7e5487ca7c29a7bd076cf9adf08"}, {"url": "https://git.kernel.org/stable/c/17ac0bc866fc624cd05f022dcd8b730c0af11bb1"}], "title": "s390/zcrypt: Improve EP11 CPRB length and overflow checks", "x_generator": {"engine": "bippy-1.2.0"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/s390/crypto/zcrypt_msgtype6.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "2976b9d2e716c7e5487ca7c29a7bd076cf9adf08", "status": "affected", "version": "e2c6d91eb8b1533753755f07803e47eceed263d0", "versionType": "git"}, {"lessThan": "17ac0bc866fc624cd05f022dcd8b730c0af11bb1", "status": "affected", "version": "e2c6d91eb8b1533753755f07803e47eceed263d0", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/s390/crypto/zcrypt_msgtype6.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "7.1"}, {"lessThan": "7.1", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.10", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/zcrypt: Improve EP11 CPRB length and overflow checks\n\nThe xcrb_msg_to_type6_ep11cprb_msgx() function lacks proper input\nvalidation, creating security vulnerabilities:\n1. Missing minimum size validation: The ep11_cprb structure and\n subsequent payload fields (pld_tag, pld_lenfmt) are copied from\n userspace without verifying sufficient buffer length.\n2. Arithmetic overflow in length calculations: CEIL4 alignment could\n overflow, bypassing size checks and enabling buffer overflows.\n3. The payload is asn1 encoded but the function just uses a simple c\n struct overlay to access some fields of the payload.\n\nFix by using size_t for length calculations, adding U32_MAX boundary\nchecks after alignment, and validating minimum request size and\nminimum reply size before copying from userspace. Do a very simple\nasn1 parsing of the payload up to the function value field."}], "id": "CVE-2026-80545", "lastModified": "2026-08-27T06:17:35.780", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-08-26T15:17:08.870", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/17ac0bc866fc624cd05f022dcd8b730c0af11bb1"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2976b9d2e716c7e5487ca7c29a7bd076cf9adf08"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: s390/zcrypt: Improve EP11 CPRB length and overflow checks", "id": "2524440", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2524440"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-120", "details": ["In the Linux kernel, the following vulnerability has been resolved:\ns390/zcrypt: Improve EP11 CPRB length and overflow checks\nThe xcrb_msg_to_type6_ep11cprb_msgx() function lacks proper input\nvalidation, creating security vulnerabilities:\n1. Missing minimum size validation: The ep11_cprb structure and\nsubsequent payload fields (pld_tag, pld_lenfmt) are copied from\nuserspace without verifying sufficient buffer length.\n2. Arithmetic overflow in length calculations: CEIL4 alignment could\noverflow, bypassing size checks and enabling buffer overflows.\n3. The payload is asn1 encoded but the function just uses a simple c\nstruct overlay to access some fields of the payload.\nFix by using size_t for length calculations, adding U32_MAX boundary\nchecks after alignment, and validating minimum request size and\nminimum reply size before copying from userspace. Do a very simple\nasn1 parsing of the payload up to the function value field.", "A flaw was found in the Linux kernel's s390/zcrypt component. This vulnerability stems from insufficient input validation in the `xcrb_msg_to_type6_ep11cprb_msgx()` function when handling EP11 Cryptographic Coprocessor Request Block (CPRB) messages. A local attacker could exploit this by crafting a malicious message, leading to arithmetic overflows in length calculations and subsequent buffer overflows. This could result in a denial of service or potentially allow for privilege escalation."], "name": "CVE-2026-80545", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-26T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-80545\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-80545\nhttps://lore.kernel.org/linux-cve-announce/2026082606-CVE-2026-80545-f190@gregkh/T"], "threat_severity": "Moderate"}