{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-80546", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.765Z", "datePublished": "2026-08-26T14:37:17.550Z", "dateUpdated": "2026-08-27T05:01:33.755Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-27T05:01:33.755Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/zcrypt: Improve CCA CPRB length and overflow checks\n\nThe xcrb_msg_to_type6cprb_msgx() function lacks proper input\nvalidation, creating security vulnerabilities:\n1. Integer overflow after CEIL4 alignment: Signed int variables could\n overflow during 4-byte boundary alignment, causing undersized\n buffer allocations or incorrect bounds checking.\n2. Missing minimum size validation: The CPRBX structure is copied from\n userspace without verifying sufficient buffer length. Undersized\n buffers cause uninitialized memory access when reading structure\n fields like cprbx.cprb_len and cprbx.domain.\n3. Arithmetic overflow in sum calculations: Adding control block and\n data block sizes could overflow, bypassing size checks and enabling\n buffer overflows.\n\nFix by using size_t for length calculations, adding U32_MAX boundary\nchecks after alignment, validating minimum control block size before\ncopying from userspace, and detecting sum calculation overflows."}], "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 bug is in xcrb_msg_to_type6cprb_msgx(), reached only from the ZSECSENDCPRB ioctl on the s390 zcrypt character device (zcrypt_unlocked_ioctl -> zsecsendcprb_ioctl -> _zcrypt_send_cprb -> prep_cca_ap_msg); there is no network, adjacent-radio, or physical-bus entry point.\nAC:L - An attacker with a zcrypt fd fully controls the ica_xcRB length fields and CPRB buffers and can craft values that bypass flawed CEIL4/sum checks on every ioctl; no race, timing dependency, or uncontrolled memory layout is required.\nPR:L - Exploitation needs only local access to a zcrypt device node with ZSECSENDCPRB permitted via zcrypt_check_ioctl(); on IBM Z/LinuxONE admins routinely delegate such access to non-root crypto service accounts through custom zcdn nodes, not init-namespace root alone.\nUI:N - The attacker triggers the flaw directly by issuing ZSECSENDCPRB with a crafted ica_xcRB from their own process; no separate victim action such as mounting a filesystem or opening a file is required.\nS:U - Impact is heap corruption and kernel memory disclosure within the host kernel address space during AP message preparation; it does not cross a VM, IOMMU, or other changed security-authority boundary.\nC:H - Undersized request_control_blk_length copies fewer than sizeof(CPRBX) bytes yet the code reads cprbx.cprb_len and cprbx.domain from uninitialized kmalloc memory; integer-overflow bypasses can also yield out-of-bounds reads beyond the allocated ap_msg buffer.\nI:H - Signed-int CEIL4 alignment and sum overflows can make ap_msg->len smaller than copied data and place req_data before the kmalloc buffer, enabling z_copy_from_user() heap buffer overflows and attacker-influenced memory corruption suitable for control-flow hijack.\nA:H - Heap underflow/overflow and corrupted AP message buffers can immediately oops or panic the kernel; prep_cca_ap_msg runs before any crypto hardware is required, so the crash primitive is repeatable from ioctl alone."}]}], "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": "50fe5133dcb46449daf2435fa705264364411129", "status": "affected", "versionType": "git"}, {"version": "e2c6d91eb8b1533753755f07803e47eceed263d0", "lessThan": "35ac6754ba6da45fd193f5ce3f665f7490b830d5", "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/50fe5133dcb46449daf2435fa705264364411129"}, {"url": "https://git.kernel.org/stable/c/35ac6754ba6da45fd193f5ce3f665f7490b830d5"}], "title": "s390/zcrypt: Improve CCA 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": "50fe5133dcb46449daf2435fa705264364411129", "status": "affected", "version": "e2c6d91eb8b1533753755f07803e47eceed263d0", "versionType": "git"}, {"lessThan": "35ac6754ba6da45fd193f5ce3f665f7490b830d5", "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 CCA CPRB length and overflow checks\n\nThe xcrb_msg_to_type6cprb_msgx() function lacks proper input\nvalidation, creating security vulnerabilities:\n1. Integer overflow after CEIL4 alignment: Signed int variables could\n overflow during 4-byte boundary alignment, causing undersized\n buffer allocations or incorrect bounds checking.\n2. Missing minimum size validation: The CPRBX structure is copied from\n userspace without verifying sufficient buffer length. Undersized\n buffers cause uninitialized memory access when reading structure\n fields like cprbx.cprb_len and cprbx.domain.\n3. Arithmetic overflow in sum calculations: Adding control block and\n data block sizes could overflow, bypassing size checks and enabling\n buffer overflows.\n\nFix by using size_t for length calculations, adding U32_MAX boundary\nchecks after alignment, validating minimum control block size before\ncopying from userspace, and detecting sum calculation overflows."}], "id": "CVE-2026-80546", "lastModified": "2026-08-27T06:17:36.067", "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": "2026-08-26T15:17:08.977", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/35ac6754ba6da45fd193f5ce3f665f7490b830d5"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/50fe5133dcb46449daf2435fa705264364411129"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: s390/zcrypt: Improve CCA CPRB length and overflow checks", "id": "2524433", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2524433"}, "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-190", "details": ["In the Linux kernel, the following vulnerability has been resolved:\ns390/zcrypt: Improve CCA CPRB length and overflow checks\nThe xcrb_msg_to_type6cprb_msgx() function lacks proper input\nvalidation, creating security vulnerabilities:\n1. Integer overflow after CEIL4 alignment: Signed int variables could\noverflow during 4-byte boundary alignment, causing undersized\nbuffer allocations or incorrect bounds checking.\n2. Missing minimum size validation: The CPRBX structure is copied from\nuserspace without verifying sufficient buffer length. Undersized\nbuffers cause uninitialized memory access when reading structure\nfields like cprbx.cprb_len and cprbx.domain.\n3. Arithmetic overflow in sum calculations: Adding control block and\ndata block sizes could overflow, bypassing size checks and enabling\nbuffer overflows.\nFix by using size_t for length calculations, adding U32_MAX boundary\nchecks after alignment, validating minimum control block size before\ncopying from userspace, and detecting sum calculation overflows.", "A flaw was found in the Linux kernel's s390/zcrypt component, specifically within the `xcrb_msg_to_type6cprb_msgx()` function. This vulnerability is due to insufficient input validation, which can lead to integer overflows during memory allocation and arithmetic operations, as well as a lack of minimum size validation for the CPRBX structure. A local attacker could exploit these issues to cause buffer overflows, potentially leading to arbitrary code execution or information disclosure."], "name": "CVE-2026-80546", "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-2026-80546\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-80546\nhttps://lore.kernel.org/linux-cve-announce/2026082607-CVE-2026-80546-79bb@gregkh/T"], "threat_severity": "Moderate"}