CVE-2026-23407 (GCVE-0-2026-23407)
Vulnerability from cvelistv5 – Published: 2026-04-01 08:36 – Updated: 2026-04-02 14:44
VLAI?
Title
apparmor: fix missing bounds check on DEFAULT table in verify_dfa()
Summary
In the Linux kernel, the following vulnerability has been resolved:
apparmor: fix missing bounds check on DEFAULT table in verify_dfa()
The verify_dfa() function only checks DEFAULT_TABLE bounds when the state
is not differentially encoded.
When the verification loop traverses the differential encoding chain,
it reads k = DEFAULT_TABLE[j] and uses k as an array index without
validation. A malformed DFA with DEFAULT_TABLE[j] >= state_count,
therefore, causes both out-of-bounds reads and writes.
[ 57.179855] ==================================================================
[ 57.180549] BUG: KASAN: slab-out-of-bounds in verify_dfa+0x59a/0x660
[ 57.180904] Read of size 4 at addr ffff888100eadec4 by task su/993
[ 57.181554] CPU: 1 UID: 0 PID: 993 Comm: su Not tainted 6.19.0-rc7-next-20260127 #1 PREEMPT(lazy)
[ 57.181558] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 57.181563] Call Trace:
[ 57.181572] <TASK>
[ 57.181577] dump_stack_lvl+0x5e/0x80
[ 57.181596] print_report+0xc8/0x270
[ 57.181605] ? verify_dfa+0x59a/0x660
[ 57.181608] kasan_report+0x118/0x150
[ 57.181620] ? verify_dfa+0x59a/0x660
[ 57.181623] verify_dfa+0x59a/0x660
[ 57.181627] aa_dfa_unpack+0x1610/0x1740
[ 57.181629] ? __kmalloc_cache_noprof+0x1d0/0x470
[ 57.181640] unpack_pdb+0x86d/0x46b0
[ 57.181647] ? srso_alias_return_thunk+0x5/0xfbef5
[ 57.181653] ? srso_alias_return_thunk+0x5/0xfbef5
[ 57.181656] ? aa_unpack_nameX+0x1a8/0x300
[ 57.181659] aa_unpack+0x20b0/0x4c30
[ 57.181662] ? srso_alias_return_thunk+0x5/0xfbef5
[ 57.181664] ? stack_depot_save_flags+0x33/0x700
[ 57.181681] ? kasan_save_track+0x4f/0x80
[ 57.181683] ? kasan_save_track+0x3e/0x80
[ 57.181686] ? __kasan_kmalloc+0x93/0xb0
[ 57.181688] ? __kvmalloc_node_noprof+0x44a/0x780
[ 57.181693] ? aa_simple_write_to_buffer+0x54/0x130
[ 57.181697] ? policy_update+0x154/0x330
[ 57.181704] aa_replace_profiles+0x15a/0x1dd0
[ 57.181707] ? srso_alias_return_thunk+0x5/0xfbef5
[ 57.181710] ? __kvmalloc_node_noprof+0x44a/0x780
[ 57.181712] ? aa_loaddata_alloc+0x77/0x140
[ 57.181715] ? srso_alias_return_thunk+0x5/0xfbef5
[ 57.181717] ? _copy_from_user+0x2a/0x70
[ 57.181730] policy_update+0x17a/0x330
[ 57.181733] profile_replace+0x153/0x1a0
[ 57.181735] ? rw_verify_area+0x93/0x2d0
[ 57.181740] vfs_write+0x235/0xab0
[ 57.181745] ksys_write+0xb0/0x170
[ 57.181748] do_syscall_64+0x8e/0x660
[ 57.181762] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 57.181765] RIP: 0033:0x7f6192792eb2
Remove the MATCH_FLAG_DIFF_ENCODE condition to validate all DEFAULT_TABLE
entries unconditionally.
Severity ?
7.8 (High)
Assigner
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Affected:
031dcc8f4e84fea37dc6f78fdc7288aa7f8386c3 , < 7c7cf05e0606f554c467e3a4dc49e2e578a755b4
(git)
Affected: 031dcc8f4e84fea37dc6f78fdc7288aa7f8386c3 , < 76b4d36c5122866452d34d8f79985e191f9c3831 (git) Affected: 031dcc8f4e84fea37dc6f78fdc7288aa7f8386c3 , < 5a68e46dfe0c8c8ffc6f425ebc4cae6238566ecc (git) Affected: 031dcc8f4e84fea37dc6f78fdc7288aa7f8386c3 , < f39e126e56c6ec1930fae51ad6bca3dae2a4c3ed (git) Affected: 031dcc8f4e84fea37dc6f78fdc7288aa7f8386c3 , < d352873bbefa7eb39995239d0b44ccdf8aaa79a4 (git) |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"security/apparmor/match.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "7c7cf05e0606f554c467e3a4dc49e2e578a755b4",
"status": "affected",
"version": "031dcc8f4e84fea37dc6f78fdc7288aa7f8386c3",
"versionType": "git"
},
{
"lessThan": "76b4d36c5122866452d34d8f79985e191f9c3831",
"status": "affected",
"version": "031dcc8f4e84fea37dc6f78fdc7288aa7f8386c3",
"versionType": "git"
},
{
"lessThan": "5a68e46dfe0c8c8ffc6f425ebc4cae6238566ecc",
"status": "affected",
"version": "031dcc8f4e84fea37dc6f78fdc7288aa7f8386c3",
"versionType": "git"
},
{
"lessThan": "f39e126e56c6ec1930fae51ad6bca3dae2a4c3ed",
"status": "affected",
"version": "031dcc8f4e84fea37dc6f78fdc7288aa7f8386c3",
"versionType": "git"
},
{
"lessThan": "d352873bbefa7eb39995239d0b44ccdf8aaa79a4",
"status": "affected",
"version": "031dcc8f4e84fea37dc6f78fdc7288aa7f8386c3",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"security/apparmor/match.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.17"
},
{
"lessThan": "4.17",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.130",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.77",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.18",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.19.*",
"status": "unaffected",
"version": "6.19.8",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.0-rc4",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.130",
"versionStartIncluding": "4.17",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.77",
"versionStartIncluding": "4.17",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.18",
"versionStartIncluding": "4.17",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.19.8",
"versionStartIncluding": "4.17",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.0-rc4",
"versionStartIncluding": "4.17",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\napparmor: fix missing bounds check on DEFAULT table in verify_dfa()\n\nThe verify_dfa() function only checks DEFAULT_TABLE bounds when the state\nis not differentially encoded.\n\nWhen the verification loop traverses the differential encoding chain,\nit reads k = DEFAULT_TABLE[j] and uses k as an array index without\nvalidation. A malformed DFA with DEFAULT_TABLE[j] \u003e= state_count,\ntherefore, causes both out-of-bounds reads and writes.\n\n[ 57.179855] ==================================================================\n[ 57.180549] BUG: KASAN: slab-out-of-bounds in verify_dfa+0x59a/0x660\n[ 57.180904] Read of size 4 at addr ffff888100eadec4 by task su/993\n\n[ 57.181554] CPU: 1 UID: 0 PID: 993 Comm: su Not tainted 6.19.0-rc7-next-20260127 #1 PREEMPT(lazy)\n[ 57.181558] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n[ 57.181563] Call Trace:\n[ 57.181572] \u003cTASK\u003e\n[ 57.181577] dump_stack_lvl+0x5e/0x80\n[ 57.181596] print_report+0xc8/0x270\n[ 57.181605] ? verify_dfa+0x59a/0x660\n[ 57.181608] kasan_report+0x118/0x150\n[ 57.181620] ? verify_dfa+0x59a/0x660\n[ 57.181623] verify_dfa+0x59a/0x660\n[ 57.181627] aa_dfa_unpack+0x1610/0x1740\n[ 57.181629] ? __kmalloc_cache_noprof+0x1d0/0x470\n[ 57.181640] unpack_pdb+0x86d/0x46b0\n[ 57.181647] ? srso_alias_return_thunk+0x5/0xfbef5\n[ 57.181653] ? srso_alias_return_thunk+0x5/0xfbef5\n[ 57.181656] ? aa_unpack_nameX+0x1a8/0x300\n[ 57.181659] aa_unpack+0x20b0/0x4c30\n[ 57.181662] ? srso_alias_return_thunk+0x5/0xfbef5\n[ 57.181664] ? stack_depot_save_flags+0x33/0x700\n[ 57.181681] ? kasan_save_track+0x4f/0x80\n[ 57.181683] ? kasan_save_track+0x3e/0x80\n[ 57.181686] ? __kasan_kmalloc+0x93/0xb0\n[ 57.181688] ? __kvmalloc_node_noprof+0x44a/0x780\n[ 57.181693] ? aa_simple_write_to_buffer+0x54/0x130\n[ 57.181697] ? policy_update+0x154/0x330\n[ 57.181704] aa_replace_profiles+0x15a/0x1dd0\n[ 57.181707] ? srso_alias_return_thunk+0x5/0xfbef5\n[ 57.181710] ? __kvmalloc_node_noprof+0x44a/0x780\n[ 57.181712] ? aa_loaddata_alloc+0x77/0x140\n[ 57.181715] ? srso_alias_return_thunk+0x5/0xfbef5\n[ 57.181717] ? _copy_from_user+0x2a/0x70\n[ 57.181730] policy_update+0x17a/0x330\n[ 57.181733] profile_replace+0x153/0x1a0\n[ 57.181735] ? rw_verify_area+0x93/0x2d0\n[ 57.181740] vfs_write+0x235/0xab0\n[ 57.181745] ksys_write+0xb0/0x170\n[ 57.181748] do_syscall_64+0x8e/0x660\n[ 57.181762] entry_SYSCALL_64_after_hwframe+0x76/0x7e\n[ 57.181765] RIP: 0033:0x7f6192792eb2\n\nRemove the MATCH_FLAG_DIFF_ENCODE condition to validate all DEFAULT_TABLE\nentries unconditionally."
}
],
"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"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-02T14:44:36.495Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/7c7cf05e0606f554c467e3a4dc49e2e578a755b4"
},
{
"url": "https://git.kernel.org/stable/c/76b4d36c5122866452d34d8f79985e191f9c3831"
},
{
"url": "https://git.kernel.org/stable/c/5a68e46dfe0c8c8ffc6f425ebc4cae6238566ecc"
},
{
"url": "https://git.kernel.org/stable/c/f39e126e56c6ec1930fae51ad6bca3dae2a4c3ed"
},
{
"url": "https://git.kernel.org/stable/c/d352873bbefa7eb39995239d0b44ccdf8aaa79a4"
}
],
"title": "apparmor: fix missing bounds check on DEFAULT table in verify_dfa()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-23407",
"datePublished": "2026-04-01T08:36:37.197Z",
"dateReserved": "2026-01-13T15:37:46.013Z",
"dateUpdated": "2026-04-02T14:44:36.495Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"nvd": "{\"cve\":{\"id\":\"CVE-2026-23407\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-04-01T09:16:16.527\",\"lastModified\":\"2026-04-02T15:16:33.720\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\napparmor: fix missing bounds check on DEFAULT table in verify_dfa()\\n\\nThe verify_dfa() function only checks DEFAULT_TABLE bounds when the state\\nis not differentially encoded.\\n\\nWhen the verification loop traverses the differential encoding chain,\\nit reads k = DEFAULT_TABLE[j] and uses k as an array index without\\nvalidation. A malformed DFA with DEFAULT_TABLE[j] \u003e= state_count,\\ntherefore, causes both out-of-bounds reads and writes.\\n\\n[ 57.179855] ==================================================================\\n[ 57.180549] BUG: KASAN: slab-out-of-bounds in verify_dfa+0x59a/0x660\\n[ 57.180904] Read of size 4 at addr ffff888100eadec4 by task su/993\\n\\n[ 57.181554] CPU: 1 UID: 0 PID: 993 Comm: su Not tainted 6.19.0-rc7-next-20260127 #1 PREEMPT(lazy)\\n[ 57.181558] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\\n[ 57.181563] Call Trace:\\n[ 57.181572] \u003cTASK\u003e\\n[ 57.181577] dump_stack_lvl+0x5e/0x80\\n[ 57.181596] print_report+0xc8/0x270\\n[ 57.181605] ? verify_dfa+0x59a/0x660\\n[ 57.181608] kasan_report+0x118/0x150\\n[ 57.181620] ? verify_dfa+0x59a/0x660\\n[ 57.181623] verify_dfa+0x59a/0x660\\n[ 57.181627] aa_dfa_unpack+0x1610/0x1740\\n[ 57.181629] ? __kmalloc_cache_noprof+0x1d0/0x470\\n[ 57.181640] unpack_pdb+0x86d/0x46b0\\n[ 57.181647] ? srso_alias_return_thunk+0x5/0xfbef5\\n[ 57.181653] ? srso_alias_return_thunk+0x5/0xfbef5\\n[ 57.181656] ? aa_unpack_nameX+0x1a8/0x300\\n[ 57.181659] aa_unpack+0x20b0/0x4c30\\n[ 57.181662] ? srso_alias_return_thunk+0x5/0xfbef5\\n[ 57.181664] ? stack_depot_save_flags+0x33/0x700\\n[ 57.181681] ? kasan_save_track+0x4f/0x80\\n[ 57.181683] ? kasan_save_track+0x3e/0x80\\n[ 57.181686] ? __kasan_kmalloc+0x93/0xb0\\n[ 57.181688] ? __kvmalloc_node_noprof+0x44a/0x780\\n[ 57.181693] ? aa_simple_write_to_buffer+0x54/0x130\\n[ 57.181697] ? policy_update+0x154/0x330\\n[ 57.181704] aa_replace_profiles+0x15a/0x1dd0\\n[ 57.181707] ? srso_alias_return_thunk+0x5/0xfbef5\\n[ 57.181710] ? __kvmalloc_node_noprof+0x44a/0x780\\n[ 57.181712] ? aa_loaddata_alloc+0x77/0x140\\n[ 57.181715] ? srso_alias_return_thunk+0x5/0xfbef5\\n[ 57.181717] ? _copy_from_user+0x2a/0x70\\n[ 57.181730] policy_update+0x17a/0x330\\n[ 57.181733] profile_replace+0x153/0x1a0\\n[ 57.181735] ? rw_verify_area+0x93/0x2d0\\n[ 57.181740] vfs_write+0x235/0xab0\\n[ 57.181745] ksys_write+0xb0/0x170\\n[ 57.181748] do_syscall_64+0x8e/0x660\\n[ 57.181762] entry_SYSCALL_64_after_hwframe+0x76/0x7e\\n[ 57.181765] RIP: 0033:0x7f6192792eb2\\n\\nRemove the MATCH_FLAG_DIFF_ENCODE condition to validate all DEFAULT_TABLE\\nentries unconditionally.\"}],\"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}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/5a68e46dfe0c8c8ffc6f425ebc4cae6238566ecc\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/76b4d36c5122866452d34d8f79985e191f9c3831\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/7c7cf05e0606f554c467e3a4dc49e2e578a755b4\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/d352873bbefa7eb39995239d0b44ccdf8aaa79a4\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/f39e126e56c6ec1930fae51ad6bca3dae2a4c3ed\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
}
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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