{"api_version":"1","generated_at":"2026-08-27T20:07:23+00:00","cve":"CVE-2026-80545","urls":{"html":"https://cve.report/CVE-2026-80545","api":"https://cve.report/api/cve/CVE-2026-80545.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-80545","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-80545"},"summary":{"title":"s390/zcrypt: Improve EP11 CPRB length and overflow checks","description":"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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-26 15:17:08","updated_at":"2026-08-27 06:17:35"},"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/2976b9d2e716c7e5487ca7c29a7bd076cf9adf08","name":"https://git.kernel.org/stable/c/2976b9d2e716c7e5487ca7c29a7bd076cf9adf08","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/17ac0bc866fc624cd05f022dcd8b730c0af11bb1","name":"https://git.kernel.org/stable/c/17ac0bc866fc624cd05f022dcd8b730c0af11bb1","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80545","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80545","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e2c6d91eb8b1533753755f07803e47eceed263d0 2976b9d2e716c7e5487ca7c29a7bd076cf9adf08 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e2c6d91eb8b1533753755f07803e47eceed263d0 17ac0bc866fc624cd05f022dcd8b730c0af11bb1 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":"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"}]}],"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 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":{"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 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."}]}],"providerMetadata":{"dateUpdated":"2026-08-27T05:01:32.688Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"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"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-80545","datePublished":"2026-08-26T14:37:16.956Z","dateReserved":"2026-08-26T14:34:25.765Z","dateUpdated":"2026-08-27T05:01:32.688Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-26 15:17:08","lastModifiedDate":"2026-08-27 06:17:35","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":"80545","Ordinal":"1","Title":"s390/zcrypt: Improve EP11 CPRB length and overflow checks","CVE":"CVE-2026-80545","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"80545","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"s390/zcrypt: Improve EP11 CPRB length and overflow checks"}]}}}