CVE-2026-89761

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89761", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.764Z", "datePublished": "2026-09-11T19:47:02.837Z", "dateUpdated": "2026-10-30T12:32:58.134Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-30T12:32:58.134Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\napparmor: fix out-of-bounds write when null terminating a label vec\n\naa_vec_unique() null terminates at vec[n - dups] when VEC_FLAG_TERMINATE\nis passed. If the components are all distinct no duplicates are dropped,\ndups is 0 and the terminator goes to vec[n], so the caller has to provide\nroom for n + 1 entries.\n\naa_label_strn_parse() sets up its vector with vec_setup(profile, vec, len,\ngfp) and then calls aa_vec_unique(vec, len, VEC_FLAG_TERMINATE), but\nvec_setup() does not reserve the terminator entry. Up to LOCAL_VEC_ENTRIES\nit uses the local array of LOCAL_VEC_ENTRIES pointers, above that it\nallocates exactly len pointers. The terminator therefore lands one entry\npast the end of the local array when len is LOCAL_VEC_ENTRIES, and one\nentry past the end of the allocation when len is larger.\n\nlen comes from the number of \"//&\" separated components in the label name\nand label_count_strn_entries() does not bound it. An unprivileged task\nreaches the parse by writing to /proc/self/attr/apparmor/current or through\nlsm_set_self_attr(2), both of which go through do_setattr(), and the name\nis parsed before the change_profile permission is checked.\nThe query_label() path behind the securityfs .access file, which is\nmode 0666, performs no permission check at all. Every component has to\nresolve to a loaded profile, so a system with policy loaded is required.\n\nThe other two VEC_FLAG_TERMINATE users work on a label vec that\naa_label_alloc() has already sized with \"+ 1 for null terminator entry on\nvec\". Reserve the same entry in vec_setup() and DEFINE_VEC(). Passing\nlen + 1 from the caller instead would move len == LOCAL_VEC_ENTRIES out of\nthe local array and into kzalloc()."}], "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 - An unprivileged local process reaches aa_label_strn_parse() by writing a compound label to /sys/kernel/security/apparmor/.access (mode 0666) via query_label()/query_data(), or via /proc/self/attr/apparmor/current and lsm_set_self_attr(2) through do_setattr(); there is no network-facing path.\nAC:L - The attacker fully controls the \"//&\"-separated label string and thus the vector length; when at least eight distinct profiles are loaded (typical Ubuntu/Debian/SUSE policy, or attacker-loaded via user namespaces) with no duplicates, aa_vec_unique() deterministically writes NULL one pointer past the stack array or heap allocation, with no race.\nPR:L - query_label() on the world-writable .access file performs no capability or change_profile check, and do_setattr() parses the name before AA_MAY_CHANGE_PROFILE is tested, so a basic unprivileged local user suffices; real root is not required.\nUI:N - The attacker opens and writes the .access query or their own procattr themselves; no victim action such as mounting a filesystem or opening a file is required.\nS:U - The out-of-bounds write corrupts kernel stack or heap within the same kernel security authority. This is standard local privilege-escalation impact, not a VM escape or IOMMU/sandbox boundary crossing.\nC:H - The one-pointer out-of-bounds write lands in adjacent stack locals or the next kmalloc object. With attacker-chosen allocation size (component count) for heap grooming, that corruption can be leveraged as a kernel memory-disclosure primitive, so confidentiality impact is high.\nI:H - aa_vec_unique() writes a NULL pointer one slot past a LOCAL_VEC_ENTRIES stack array or a heap buffer sized exactly to the attacker-chosen component count. An out-of-bounds write that corrupts adjacent kernel objects is a write primitive suitable for control-flow hijacking.\nA:H - Corrupting an adjacent stack pointer, heap object, or stack canary can oops, panic, or hang the kernel; the unexploited NULL write alone is sufficient for denial of service."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["security/apparmor/include/label.h"], "versions": [{"version": "f1bd904175e8190ce14aedee37e207ab51fe3b30", "lessThan": "0d4cb3af82556afc48f90fd3e8a126ff32343f41", "status": "affected", "versionType": "git"}, {"version": "f1bd904175e8190ce14aedee37e207ab51fe3b30", "lessThan": "40fdee1cb4f18e6a1a21a891ae4735bcd4d35026", "status": "affected", "versionType": "git"}, {"version": "f1bd904175e8190ce14aedee37e207ab51fe3b30", "lessThan": "57bb24025f450728f342d8e08cd3909c89361d90", "status": "affected", "versionType": "git"}, {"version": "f1bd904175e8190ce14aedee37e207ab51fe3b30", "lessThan": "b17c8f5dcb36a032688847b2bce4bd813b4baad1", "status": "affected", "versionType": "git"}, {"version": "f1bd904175e8190ce14aedee37e207ab51fe3b30", "lessThan": "9124e078ea2250d8d01d2162a550acb01ef5bf48", "status": "affected", "versionType": "git"}, {"version": "f1bd904175e8190ce14aedee37e207ab51fe3b30", "lessThan": "28069434aef66b9d084f0609b7a29c171846815e", "status": "affected", "versionType": "git"}, {"version": "f1bd904175e8190ce14aedee37e207ab51fe3b30", "lessThan": "36bdd0b45ec3f4822832a56e9db8674c8450dfce", "status": "affected", "versionType": "git"}, {"version": "f1bd904175e8190ce14aedee37e207ab51fe3b30", "lessThan": "9f1e40193eef7f047e6b77cfb4b4cafdecd7a123", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["security/apparmor/include/label.h"], "versions": [{"version": "4.13", "status": "affected"}, {"version": "0", "lessThan": "4.13", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.273", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.224", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.191", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.160", "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": 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write when null terminating a label vec", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["security/apparmor/include/label.h"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "0d4cb3af82556afc48f90fd3e8a126ff32343f41", "status": "affected", "version": "f1bd904175e8190ce14aedee37e207ab51fe3b30", "versionType": "git"}, {"lessThan": "40fdee1cb4f18e6a1a21a891ae4735bcd4d35026", "status": "affected", "version": "f1bd904175e8190ce14aedee37e207ab51fe3b30", "versionType": "git"}, {"lessThan": "57bb24025f450728f342d8e08cd3909c89361d90", "status": "affected", "version": "f1bd904175e8190ce14aedee37e207ab51fe3b30", "versionType": "git"}, {"lessThan": "b17c8f5dcb36a032688847b2bce4bd813b4baad1", "status": "affected", "version": "f1bd904175e8190ce14aedee37e207ab51fe3b30", "versionType": "git"}, {"lessThan": "9124e078ea2250d8d01d2162a550acb01ef5bf48", "status": "affected", "version": "f1bd904175e8190ce14aedee37e207ab51fe3b30", "versionType": "git"}, {"lessThan": "28069434aef66b9d084f0609b7a29c171846815e", "status": "affected", "version": "f1bd904175e8190ce14aedee37e207ab51fe3b30", "versionType": "git"}, {"lessThan": "36bdd0b45ec3f4822832a56e9db8674c8450dfce", "status": "affected", "version": "f1bd904175e8190ce14aedee37e207ab51fe3b30", "versionType": "git"}, {"lessThan": "9f1e40193eef7f047e6b77cfb4b4cafdecd7a123", "status": "affected", "version": "f1bd904175e8190ce14aedee37e207ab51fe3b30", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["security/apparmor/include/label.h"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "4.13"}, {"lessThan": "4.13", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.273", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.224", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.191", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.160", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.109", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.50", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "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\napparmor: fix out-of-bounds write when null terminating a label vec\n\naa_vec_unique() null terminates at vec[n - dups] when VEC_FLAG_TERMINATE\nis passed. If the components are all distinct no duplicates are dropped,\ndups is 0 and the terminator goes to vec[n], so the caller has to provide\nroom for n + 1 entries.\n\naa_label_strn_parse() sets up its vector with vec_setup(profile, vec, len,\ngfp) and then calls aa_vec_unique(vec, len, VEC_FLAG_TERMINATE), but\nvec_setup() does not reserve the terminator entry. Up to LOCAL_VEC_ENTRIES\nit uses the local array of LOCAL_VEC_ENTRIES pointers, above that it\nallocates exactly len pointers. The terminator therefore lands one entry\npast the end of the local array when len is LOCAL_VEC_ENTRIES, and one\nentry past the end of the allocation when len is larger.\n\nlen comes from the number of \"//&\" separated components in the label name\nand label_count_strn_entries() does not bound it. An unprivileged task\nreaches the parse by writing to /proc/self/attr/apparmor/current or through\nlsm_set_self_attr(2), both of which go through do_setattr(), and the name\nis parsed before the change_profile permission is checked.\nThe query_label() path behind the securityfs .access file, which is\nmode 0666, performs no permission check at all. Every component has to\nresolve to a loaded profile, so a system with policy loaded is required.\n\nThe other two VEC_FLAG_TERMINATE users work on a label vec that\naa_label_alloc() has already sized with \"+ 1 for null terminator entry on\nvec\". Reserve the same entry in vec_setup() and DEFINE_VEC(). Passing\nlen + 1 from the caller instead would move len == LOCAL_VEC_ENTRIES out of\nthe local array and into kzalloc()."}], "id": "CVE-2026-89761", "lastModified": "2026-10-30T13:20:28.500", "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": "2026-09-11T20:20:07.243", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/0d4cb3af82556afc48f90fd3e8a126ff32343f41"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/28069434aef66b9d084f0609b7a29c171846815e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/36bdd0b45ec3f4822832a56e9db8674c8450dfce"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/40fdee1cb4f18e6a1a21a891ae4735bcd4d35026"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/57bb24025f450728f342d8e08cd3909c89361d90"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/9124e078ea2250d8d01d2162a550acb01ef5bf48"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/9f1e40193eef7f047e6b77cfb4b4cafdecd7a123"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b17c8f5dcb36a032688847b2bce4bd813b4baad1"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Kernel: AppArmor out-of-bounds write allows local denial of service or privilege escalation", "id": "2532235", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532235"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:H", "status": "draft"}, "cwe": "CWE-787", "details": ["A flaw was found in the Linux kernel's AppArmor security module. An out-of-bounds write vulnerability exists when null terminating a label vector due to improper memory allocation. An unprivileged local attacker can exploit this by writing to specific system files, potentially leading to a denial of service (DoS) or, in some cases, privilege escalation. This vulnerability requires an AppArmor policy to be loaded on the system."], "name": "CVE-2026-89761", "public_date": "2026-09-11T19:47:02Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89761\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89761\nhttps://git.kernel.org/stable/c/28069434aef66b9d084f0609b7a29c171846815e\nhttps://git.kernel.org/stable/c/36bdd0b45ec3f4822832a56e9db8674c8450dfce\nhttps://git.kernel.org/stable/c/9124e078ea2250d8d01d2162a550acb01ef5bf48\nhttps://git.kernel.org/stable/c/9f1e40193eef7f047e6b77cfb4b4cafdecd7a123"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f1bd904175e8190ce14aedee37e207ab51fe3b30,9124e078ea2250d8d01d2162a550acb01ef5bf48)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f1bd904175e8190ce14aedee37e207ab51fe3b30,28069434aef66b9d084f0609b7a29c171846815e)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f1bd904175e8190ce14aedee37e207ab51fe3b30,36bdd0b45ec3f4822832a56e9db8674c8450dfce)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f1bd904175e8190ce14aedee37e207ab51fe3b30,9f1e40193eef7f047e6b77cfb4b4cafdecd7a123)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "4.13"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,4.13)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.109,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.50,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.4,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-09-12T05:15:06.923894+00:00", "updated": "2026-09-15T19:15:16.159782+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}