{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-80921", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.801Z", "datePublished": "2026-09-09T16:19:42.335Z", "dateUpdated": "2026-10-19T08:45:04.791Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:45:04.791Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: s390: vsie: zero stale crypto bits\n\nWhen shadowing crypto access bits from a format0 apcb (crycb 0 or 1),\nthe bits 64..255 are unchanged from whatever is in the vsie page in the\ncrycb and thus in the apcb. This gives a nested guest potential access\nto a device no longer available. Zero out the remaining bits." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is reached when an s390 KVM guest executes the privileged SIE instruction (B2/14), intercepted through handle_instruction() to kvm_s390_handle_vsie() and setup_apcb10(); that is a local guest/KVM ioctl path with no network, Bluetooth, or USB exposure.\nAC:L - An L1 guest that first runs a FORMAT-2 nested SCB (setup_apcb11 fills all 256 APCB bits) and then a FORMAT-0/1 SCB on a recycled vsie page hits setup_apcb10() deterministically; get_vsie_page() reuses pages without clearing crycb, so leftover bits 64-255 persist with no race or uncontrolled memory layout.\nPR:L - SIE requires guest supervisor state, i.e. the tenant guest kernel or an unprivileged host kvm-group user running QEMU, not host root; kvm_s390_handle_vsie() has no host capability gate, and user namespaces cannot substitute for this path, so privileges stay Low rather than High.\nUI:N - The attacker guest issues SIE and uses the over-permissive shadow APCB itself; vsie page reuse and crycb shadowing run automatically inside KVM with no victim mount, click, or other user action.\nS:C - Leftover APCB bits grant a nested guest millicode-enforced access to host AP adapters/domains outside its delegated matrix, crossing the KVM nested-virt and vfio-ap passthrough boundary into another guest's or the host zcrypt authority, equivalent to an IOMMU/device isolation bypass.\nC:H - Unauthorized APQNs let the nested guest issue NQAP/DQAP against queues that may now belong to the host zcrypt stack or another tenant, disclosing cryptographic request/response data and key material on those adapters/domains.\nI:H - The nested guest can enqueue arbitrary AP requests and change hardware queue state on adapters and domains 64-255 that the current shadow should have cleared, corrupting crypto operations the host believes are exclusive to another consumer.\nA:H - With those leftover APQNs the nested guest can PQAP(ZAPQ)-reset or flood shared queues, denying host or sibling-guest crypto services (pkey, secure-key LUKS, openCryptoki) that depend on the same physical adapter/domain." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/s390/kvm/vsie.c" ], "versions": [ { "version": "6b79de4b056e5a2febc0c61233d8f0ad7868e49c", "lessThan": "d110b3297f11ef227098b8a82ade2d5f123b7d2f", "status": "affected", "versionType": "git" }, { "version": "6b79de4b056e5a2febc0c61233d8f0ad7868e49c", "lessThan": "59d51550b5cb916bda037673a721a404b3b47a0d", "status": "affected", "versionType": "git" }, { "version": "6b79de4b056e5a2febc0c61233d8f0ad7868e49c", "lessThan": "f6079dca67eccb5eabef9f72437948c66dc5131f", "status": "affected", "versionType": "git" }, { "version": "6b79de4b056e5a2febc0c61233d8f0ad7868e49c", "lessThan": "087c19cc60a8caa1a08e1e434c8be2caf6c27733", "status": "affected", "versionType": "git" }, { "version": "6b79de4b056e5a2febc0c61233d8f0ad7868e49c", "lessThan": "7d23489f51109e3ebba5b5db8c5f0185af7b7fdf", "status": "affected", "versionType": "git" }, { "version": "6b79de4b056e5a2febc0c61233d8f0ad7868e49c", "lessThan": "935eeba276012916c76243e5cbb843efd8fdb75d", "status": "affected", "versionType": "git" }, { "version": "6b79de4b056e5a2febc0c61233d8f0ad7868e49c", "lessThan": "d4bcd2df6d0d2af916b4fe1a533958778ea7c45b", "status": "affected", "versionType": "git" }, { "version": "6b79de4b056e5a2febc0c61233d8f0ad7868e49c", "lessThan": "29b4f7bc2991313bd3e6f6fb8fdf1b173f086dd6", "status": "affected", "versionType": "git" }, { "version": "6b79de4b056e5a2febc0c61233d8f0ad7868e49c", "lessThan": "34d5b5b646c91cfb9338d7a12c955a70ffb8c66b", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/s390/kvm/vsie.c" ], "versions": [ { "version": "4.20", "status": "affected" }, { "version": "0", "lessThan": "4.20", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.269", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.220", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.187", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.156", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.108", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.49", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.13", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.3", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "4.20", "versionEndExcluding": "5.10.269" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "5.15.220" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.1.187" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.6.156" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.12.108" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.18.49" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "7.1.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "7.2.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/d110b3297f11ef227098b8a82ade2d5f123b7d2f" }, { "url": "https://git.kernel.org/stable/c/59d51550b5cb916bda037673a721a404b3b47a0d" }, { "url": "https://git.kernel.org/stable/c/f6079dca67eccb5eabef9f72437948c66dc5131f" }, { "url": "https://git.kernel.org/stable/c/087c19cc60a8caa1a08e1e434c8be2caf6c27733" }, { "url": "https://git.kernel.org/stable/c/7d23489f51109e3ebba5b5db8c5f0185af7b7fdf" }, { "url": "https://git.kernel.org/stable/c/935eeba276012916c76243e5cbb843efd8fdb75d" }, { "url": "https://git.kernel.org/stable/c/d4bcd2df6d0d2af916b4fe1a533958778ea7c45b" }, { "url": "https://git.kernel.org/stable/c/29b4f7bc2991313bd3e6f6fb8fdf1b173f086dd6" }, { "url": "https://git.kernel.org/stable/c/34d5b5b646c91cfb9338d7a12c955a70ffb8c66b" } ], "title": "KVM: s390: vsie: zero stale crypto bits", "x_generator": { "engine": "bippy-1.2.0" } } } }