CVE-2026-23407
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-125 · Out-of-bounds read
- Record status
- Analyzed
Affected
- Linux Kernel < 5.10.253
- Linux Kernel < 5.15.203
- Linux Kernel < 6.1.169
- Linux Kernel < 6.6.130
- Linux Kernel < 6.12.77
- Linux Kernel < 6.18.18
- Linux Kernel < 6.19.8
- Linux Kernel 4.17
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-23407.md and follow it. Check whether this project is affected by CVE-2026-23407. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/22094c996968a7c5b59cd3fc9fcbdfdd46d02fec
- https://git.kernel.org/stable/c/555829fd91eaf0711e369b0a92aecb0f0aa3281f
- https://git.kernel.org/stable/c/5a68e46dfe0c8c8ffc6f425ebc4cae6238566ecc
- https://git.kernel.org/stable/c/76b4d36c5122866452d34d8f79985e191f9c3831
- https://git.kernel.org/stable/c/7c7cf05e0606f554c467e3a4dc49e2e578a755b4
- https://git.kernel.org/stable/c/a75e12ca90c9e70ba10fee1be2f63cdd63d91a7c
- https://git.kernel.org/stable/c/d352873bbefa7eb39995239d0b44ccdf8aaa79a4
- https://git.kernel.org/stable/c/f39e126e56c6ec1930fae51ad6bca3dae2a4c3ed
References
- https://git.kernel.org/stable/c/22094c996968a7c5b59cd3fc9fcbdfdd46d02fec
- https://git.kernel.org/stable/c/555829fd91eaf0711e369b0a92aecb0f0aa3281f
- https://git.kernel.org/stable/c/5a68e46dfe0c8c8ffc6f425ebc4cae6238566ecc
- https://git.kernel.org/stable/c/76b4d36c5122866452d34d8f79985e191f9c3831
- https://git.kernel.org/stable/c/7c7cf05e0606f554c467e3a4dc49e2e578a755b4
- https://git.kernel.org/stable/c/a75e12ca90c9e70ba10fee1be2f63cdd63d91a7c
- https://git.kernel.org/stable/c/d352873bbefa7eb39995239d0b44ccdf8aaa79a4
- https://git.kernel.org/stable/c/f39e126e56c6ec1930fae51ad6bca3dae2a4c3ed