{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89653", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.742Z", "datePublished": "2026-09-11T19:45:43.261Z", "dateUpdated": "2026-10-19T08:50:24.862Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:50:24.862Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nceph: reject export_targets ranks >= CEPH_MAX_MDS in mdsmap decode\n\nMDSMap export_targets entries are monitor controlled. check_new_map()\nuses each entry as a bit number in a fixed stack bitmap, so a rank\noutside the protocol namespace can make set_bit() write past the end of\nthe array.\n\nReject ranks outside CEPH_MAX_MDS while decoding the map. Do not\nvalidate against possible_max_rank here because maps may legitimately\nreference ranks beyond a temporarily reduced max_mds." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - A crafted MDSMap arrives in CEPH_MSG_MDS_MAP over the Ceph messenger TCP session from a monitor or MDS; extra_mon_dispatch() and mds_dispatch() deliver it to ceph_mdsc_handle_mdsmap() on already-mounted CephFS/Rook/Kubernetes clients without a local syscall.\nAC:L - The monitor fully controls each export_targets[] u32; after the first map is stored, a later epoch reaches check_new_map() and set_bit() with an attacker-chosen bit number, overflowing the stack bitmap with no race or special layout.\nPR:N - The attacker is the remote Ceph monitor or MDS peer and needs no Linux UID, capability, or init-namespace root on the victim, matching other Ceph client decode CVEs such as CVE-2026-68159.\nUI:N - Once CephFS is mounted, MDS maps are subscribed and applied automatically in the ceph-msgr worker; a malicious peer can push a new epoch without any further interactive victim action.\nS:U - The stack out-of-bounds write corrupts kernel memory on the Ceph client host only and does not cross a VM, IOMMU, or sandbox security authority.\nC:H - set_bit() with an attacker-chosen rank writes past the fixed stack bitmap in check_new_map(), corrupting adjacent kernel stack contents; this memory-corruption primitive can be leveraged for information disclosure.\nI:H - The overflow is a stack out-of-bounds write of attacker-selected bits at a u32-controlled offset from the targets[] array, enabling control-flow hijack and arbitrary kernel writes.\nA:H - An out-of-range bit index makes set_bit() write off the stack object, causing a KASAN stack-out-of-bounds report or kernel oops/panic that a malicious monitor can repeat with each new map epoch." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ceph/mdsmap.c" ], "versions": [ { "version": "d517b3983dd3106ca92d6c5d0d09415a4a09481c", "lessThan": "3740c88ca9cb2210a8dbdd55ea4cec119fbe86fe", "status": "affected", "versionType": "git" }, { "version": "d517b3983dd3106ca92d6c5d0d09415a4a09481c", "lessThan": "8c823bbab3c24e657469a84db96902ba82d4e8bb", "status": "affected", "versionType": "git" }, { "version": "d517b3983dd3106ca92d6c5d0d09415a4a09481c", "lessThan": "c4addccd05bacbef2144b4db14853d0308a218ac", "status": "affected", "versionType": "git" }, { "version": "d517b3983dd3106ca92d6c5d0d09415a4a09481c", "lessThan": "736adee11af36e407ed902264f8b2fb5cf94b62f", "status": "affected", "versionType": "git" }, { "version": "d517b3983dd3106ca92d6c5d0d09415a4a09481c", "lessThan": "4d298880f82c42383b36946bafde7ccf4d804c9b", "status": "affected", "versionType": "git" }, { "version": "d517b3983dd3106ca92d6c5d0d09415a4a09481c", "lessThan": "96c3f5fbb0d5386e7111426f047f98cec4586674", "status": "affected", "versionType": "git" }, { "version": "d517b3983dd3106ca92d6c5d0d09415a4a09481c", "lessThan": "aedc9053d909508a5f56c3f49f885fc030df4730", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ceph/mdsmap.c" ], "versions": [ { "version": "5.15", "status": "affected" }, { "version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.4", "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": "5.15", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.12.109" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.18.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/3740c88ca9cb2210a8dbdd55ea4cec119fbe86fe" }, { "url": "https://git.kernel.org/stable/c/8c823bbab3c24e657469a84db96902ba82d4e8bb" }, { "url": "https://git.kernel.org/stable/c/c4addccd05bacbef2144b4db14853d0308a218ac" }, { "url": "https://git.kernel.org/stable/c/736adee11af36e407ed902264f8b2fb5cf94b62f" }, { "url": "https://git.kernel.org/stable/c/4d298880f82c42383b36946bafde7ccf4d804c9b" }, { "url": "https://git.kernel.org/stable/c/96c3f5fbb0d5386e7111426f047f98cec4586674" }, { "url": "https://git.kernel.org/stable/c/aedc9053d909508a5f56c3f49f885fc030df4730" } ], "title": "ceph: reject export_targets ranks >= CEPH_MAX_MDS in mdsmap decode", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-89653", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:25:22.176850Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:26:46.987Z" } } ] } }