CVE-2026-23407

HIGHNVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-04-01. NVD baseline CVSS 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: None knownExposed: 0

A fix is available — apply it.

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] [ 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.

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
40(Track)
EG Risk 40/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity78% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
8%
KEV
Not listed

Published

April 1, 2026

Last Modified

April 24, 2026

Advisory Details (8)

Auto-updated Jun 10, 2026
No patch confirmed yet.
generic

apparmor: fix missing bounds check on DEFAULT table in verify_dfa() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f39e126e56c6ec1930fae51ad6bca3dae2a4c3ed
generic

apparmor: fix missing bounds check on DEFAULT table in verify_dfa() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d352873bbefa7eb39995239d0b44ccdf8aaa79a4
generic

apparmor: fix missing bounds check on DEFAULT table in verify_dfa() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a75e12ca90c9e70ba10fee1be2f63cdd63d91a7c
generic

apparmor: fix missing bounds check on DEFAULT table in verify_dfa() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/7c7cf05e0606f554c467e3a4dc49e2e578a755b4
generic

apparmor: fix missing bounds check on DEFAULT table in verify_dfa() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/76b4d36c5122866452d34d8f79985e191f9c3831
generic

apparmor: fix missing bounds check on DEFAULT table in verify_dfa() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/5a68e46dfe0c8c8ffc6f425ebc4cae6238566ecc
generic

apparmor: fix missing bounds check on DEFAULT table in verify_dfa() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/555829fd91eaf0711e369b0a92aecb0f0aa3281f
generic

apparmor: fix missing bounds check on DEFAULT table in verify_dfa() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/22094c996968a7c5b59cd3fc9fcbdfdd46d02fec

Vendor Advisories for CVE-2026-23407(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(11)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-azure-fips-5.15 (5.15.0.1109.94) @ jammy2026-06-11ubuntu
ubuntulinux-tools-oem-6.17 (6.17.0-1017.17) @ noble2026-06-11ubuntu
ubuntulinux-tools-azure-lts-22.04 (5.15.0.1109.107) @ jammy2026-06-11ubuntu
ubuntulinux-tools-intel-iot-realtime-5.15 (5.15.0.1096.100) @ jammy2026-06-11ubuntu
ubuntulinux-tools-azure-edge (5.4.0.1161.167~18.04.1) @ bionic2026-06-11ubuntu
ubuntulinux-tools-raspi2-hwe-18.04-edge (5.4.0.1139.170) @ focal2026-06-11ubuntu
ubuntulinux-tools-azure-fips-6.8 (6.8.0-1052.58+fips1) @ noble2026-06-11ubuntu
ubuntulinux-tools-bluefield-5.4 (5.4.0.1116.112) @ focal2026-06-11ubuntu
ubuntulinux-tools-azure-edge (5.15.0.1110.119~20.04.1) @ focal2026-06-11ubuntu
ubuntulinux-xilinx-zynqmp (6.8.0.1029.30) @ noble2026-06-11ubuntu
linuxKernel @ 5.10.253—osv

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(10)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 12× in last 7d / 48× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 138 total refreshes for this CVE.

  1. 2026-07-27 14:13 UTCEPSS rescore
  2. 2026-07-26 14:54 UTCEPSS rescore
  3. 2026-07-26 14:54 UTCEPSS rescore
  4. 2026-07-25 14:17 UTCEPSS rescore
  5. 2026-07-25 14:17 UTCEPSS rescore
  6. 2026-07-24 14:17 UTCEPSS rescore
  7. 2026-07-23 14:18 UTCEPSS rescore
  8. 2026-07-23 14:18 UTCEPSS rescore
  9. 2026-07-23 03:07 UTCEG score recompute
  10. 2026-07-22 14:08 UTCEPSS rescore
  11. 2026-07-21 15:24 UTCEPSS rescore
  12. 2026-07-21 15:24 UTCEPSS rescore
  13. 2026-07-20 17:08 UTCEPSS rescore
  14. 2026-07-19 14:31 UTCEPSS rescore
  15. 2026-07-19 14:31 UTCEPSS rescore
  16. 2026-07-19 02:29 UTCEPSS rescore
  17. 2026-07-19 02:28 UTCEPSS rescore
  18. 2026-07-18 10:04 UTCEPSS rescore
  19. 2026-07-18 10:04 UTCEPSS rescore
  20. 2026-07-17 04:24 UTCOSV refresh
  21. 2026-07-16 17:03 UTCEPSS rescore
  22. 2026-07-16 17:03 UTCEPSS rescore
  23. 2026-07-15 16:57 UTCEPSS rescore
  24. 2026-07-15 16:57 UTCEPSS rescore
  25. 2026-07-15 02:00 UTCEPSS rescore
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  1. 2026-07-15 02:00 UTCEPSS rescore
  2. 2026-07-13 22:30 UTCEPSS rescore
  3. 2026-07-13 06:13 UTCEPSS rescore
  4. 2026-07-13 06:13 UTCEPSS rescore
  5. 2026-07-12 05:46 UTCEPSS rescore
  6. 2026-07-12 05:46 UTCEPSS rescore
  7. 2026-07-11 08:27 UTCEPSS rescore
  8. 2026-07-09 19:10 UTCEPSS rescore
  9. 2026-07-08 15:15 UTCEPSS rescore
  10. 2026-07-08 15:15 UTCEPSS rescore
  11. 2026-07-07 13:46 UTCEPSS rescore
  12. 2026-07-06 16:27 UTCEPSS rescore
  13. 2026-07-06 16:27 UTCEPSS rescore
  14. 2026-07-06 02:23 UTCEPSS rescore
  15. 2026-07-06 02:23 UTCEPSS rescore
  16. 2026-07-05 02:30 UTCEPSS rescore
  17. 2026-07-04 06:31 UTCEPSS rescore
  18. 2026-07-04 06:31 UTCEPSS rescore
  19. 2026-07-01 15:06 UTCEPSS rescore
  20. 2026-07-01 15:06 UTCEPSS rescore
  21. 2026-06-30 23:22 UTCEPSS rescore
  22. 2026-06-30 23:22 UTCEPSS rescore
  23. 2026-06-29 14:06 UTCEPSS rescore
  24. 2026-06-28 14:07 UTCEPSS rescore
  25. 2026-06-28 14:07 UTCEPSS rescore
  26. 2026-06-28 04:56 UTCEPSS rescore
  27. 2026-06-28 04:56 UTCEPSS rescore
  28. 2026-06-27 03:08 UTCEPSS rescore
  29. 2026-06-25 13:49 UTCEPSS rescore
  30. 2026-06-25 13:49 UTCEPSS rescore
  31. 2026-06-24 14:05 UTCEPSS rescore
  32. 2026-06-24 14:05 UTCEPSS rescore
  33. 2026-06-23 21:33 UTCEPSS rescore
  34. 2026-06-23 21:32 UTCEPSS rescore
  35. 2026-06-22 14:25 UTCEPSS rescore
  36. 2026-06-22 14:25 UTCEPSS rescore
  37. 2026-06-21 14:56 UTCEPSS rescore
  38. 2026-06-21 14:56 UTCEPSS rescore
  39. 2026-06-21 01:59 UTCEPSS rescore
  40. 2026-06-21 01:59 UTCEPSS rescore
  41. 2026-06-19 19:25 UTCEPSS rescore
  42. 2026-06-19 19:25 UTCEPSS rescore
  43. 2026-06-18 17:52 UTCEPSS rescore
  44. 2026-06-17 17:53 UTCEPSS rescore
  45. 2026-06-17 17:53 UTCEPSS rescore
  46. 2026-06-16 17:52 UTCEPSS rescore
  47. 2026-06-15 17:48 UTCEPSS rescore
  48. 2026-06-14 23:18 UTCEPSS rescore
  49. 2026-06-13 23:00 UTCEPSS rescore
  50. 2026-06-12 23:12 UTCEPSS rescore
  51. 2026-06-12 23:12 UTCEPSS rescore
  52. 2026-06-11 22:28 UTCVendor advisory
  53. 2026-06-11 22:27 UTCGHSA enrichment
  54. 2026-06-11 14:00 UTCEPSS rescore
  55. 2026-06-10 22:18 UTCEPSS rescore
  56. 2026-06-10 17:24 UTCVendor advisory
  57. 2026-06-10 17:24 UTCGHSA enrichment
  58. 2026-06-10 04:05 UTCVendor advisory
  59. 2026-06-10 04:05 UTCGHSA enrichment
  60. 2026-06-09 14:55 UTCVendor advisory
  61. 2026-06-09 14:55 UTCGHSA enrichment
  62. 2026-06-08 14:17 UTCEPSS rescore
  63. 2026-06-08 14:17 UTCEPSS rescore
  64. 2026-06-08 13:56 UTCVendor advisory
  65. 2026-06-08 13:55 UTCGHSA enrichment
  66. 2026-06-08 00:42 UTCVendor advisory
  67. 2026-06-08 00:42 UTCGHSA enrichment
  68. 2026-06-07 15:25 UTCEPSS rescore
  69. 2026-06-07 15:24 UTCEPSS rescore
  70. 2026-06-07 11:20 UTCVendor advisory
  71. 2026-06-07 11:20 UTCGHSA enrichment
  72. 2026-06-06 13:47 UTCEPSS rescore
  73. 2026-06-06 13:47 UTCEPSS rescore
  74. 2026-06-06 13:47 UTCEPSS rescore
  75. 2026-06-05 22:47 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-23407?
CVE-2026-23407 is a high vulnerability published on April 1, 2026. In the Linux kernel, the following vulnerability has been resolved: apparmor: fix missing bounds check on DEFAULT table in verify_dfa() The verifydfa() function only checks DEFAULTTABLE bounds when the state is not differentially encoded. When the verification loop traverses the differential…
When was CVE-2026-23407 disclosed?
CVE-2026-23407 was first published in the National Vulnerability Database on April 1, 2026, with the most recent update on April 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-23407 actively exploited?
CVE-2026-23407 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 92.1% of all scored CVEs.
What is the CVSS score of CVE-2026-23407?
CVE-2026-23407 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-23407?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-23407, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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