{"api_version":"1","generated_at":"2026-08-27T20:07:30+00:00","cve":"CVE-2026-80546","urls":{"html":"https://cve.report/CVE-2026-80546","api":"https://cve.report/api/cve/CVE-2026-80546.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-80546","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-80546"},"summary":{"title":"s390/zcrypt: Improve CCA CPRB length and overflow checks","description":"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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-26 15:17:08","updated_at":"2026-08-27 06:17:36"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"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","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/50fe5133dcb46449daf2435fa705264364411129","name":"https://git.kernel.org/stable/c/50fe5133dcb46449daf2435fa705264364411129","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/35ac6754ba6da45fd193f5ce3f665f7490b830d5","name":"https://git.kernel.org/stable/c/35ac6754ba6da45fd193f5ce3f665f7490b830d5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80546","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80546","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e2c6d91eb8b1533753755f07803e47eceed263d0 50fe5133dcb46449daf2435fa705264364411129 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e2c6d91eb8b1533753755f07803e47eceed263d0 35ac6754ba6da45fd193f5ce3f665f7490b830d5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.1","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.10 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"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"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.10","versionStartIncluding":"7.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"7.1","vulnerable":true}],"negate":false,"operator":"OR"}]}],"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":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"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."}]}],"providerMetadata":{"dateUpdated":"2026-08-27T05:01:33.755Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"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"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-80546","datePublished":"2026-08-26T14:37:17.550Z","dateReserved":"2026-08-26T14:34:25.765Z","dateUpdated":"2026-08-27T05:01:33.755Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-26 15:17:08","lastModifiedDate":"2026-08-27 06:17:36","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"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","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"80546","Ordinal":"1","Title":"s390/zcrypt: Improve CCA CPRB length and overflow checks","CVE":"CVE-2026-80546","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"80546","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"s390/zcrypt: Improve CCA CPRB length and overflow checks"}]}}}