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CVE-2026-72462
apparmor: fix race in unix socket mediation when peer_path is used
Published 2026-08-15 (2 months ago) by the Linux kernel CNA. Subsystem security/apparmor. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-72462 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | not affected | 6.1.190-1 | Nothing to do. bookworm never shipped the vulnerable code. |
| Debian 13trixie | not affected | 6.12.113-1 | Nothing to do. trixie never shipped the vulnerable code. |
| Debian 14forky | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
The holding a reference to the peer_sk is not enough to ensure access to the peer sk path. Accessing the path outside of the state lock allows for a race with unix_release_sock(). Fix this by taking the state lock and getting a reference to the path under lock. Ideally for connected sockets we would cache this information so we don't have to take the lock here. But for now just fix the race.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
security/apparmor/af_unix.c
- What this is
- APPARMOR SECURITY MODULEMAINTAINERS section matched on security/apparmor/ · apparmor@lists.ubuntu.com · Supported
Check it on the machine
grep -w CONFIG_SECURITY_APPARMOR /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
Show whether Debian builds this, per release
Debian builds this code. Every release with an answer below compiles the affected file into the kernels it ships. The build rule could not be established for 2 releases, so nothing is claimed about those.
- bookworm, trixie?
- forky, sidy
- ?
- not established - no Makefile entry for the affected file
- y
- built into the kernel image on every flavour - only a patch removes it
Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.
- Build switch
- CONFIG_SECURITY_APPARMOR
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-08-15 (2 months ago)source
- CVSS
- 8.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.17%, higher than 6.3% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- Subsystem
- security/apparmor
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.17 | 6.18.40 | d8ea44f6090c |
| 6.17 | 7.1.5 | d680472db988 |
| 6.17 | 7.2 | b1aea2c19607 |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:LAttack vector, local
- Exploitation requires local Unix domain socket syscalls (connect/read/write/close) that reach the AppArmor file_permission LSM hook on a connected PF_UNIX socket; there is no network packet or remote protocol path to this code.
- AC:LAttack complexity, low
- The attacker controls both ends of the race by concurrently I/O'ing on an abstract/anonymous socket connected to a filesystem-bound peer while closing the peer socket, repeatedly timing read/write against peer teardown until the window is hit.
- PR:LPrivileges required, low
- Any unprivileged local user can create and connect Unix sockets and trigger revalidation on confined workloads (snaps, containers, desktop services on AppArmor-enabled Ubuntu/Debian); no real-root or init-namespace capabilities are required.
- UI:NUser interaction, none
- Exploitation is fully attacker-driven through automated concurrent socket operations and does not require any victim user action such as opening files or mounting filesystems.
- S:CScope, changed
- Winning the race can bypass AppArmor Unix peer_path mediation (implicit allow when dentry is cleared) or corrupt kernel objects via dentry UAF, crossing the AppArmor confinement boundary that normally separates confined from unconfined authority.
- C:HConfidentiality impact, high
- Use-after-free of the peer socket's dentry/inode during unix_fs_perm/aa_path_perm allows dereferencing freed kernel heap memory, which per kernel CVSS guidance for UAF enables arbitrary kernel memory disclosure primitives.
- I:HIntegrity impact, high
- The UAF on struct path/dentry/inode is heap memory corruption that can be leveraged for arbitrary kernel writes and control-flow hijack; the race can also silently bypass AppArmor peer filesystem permission enforcement.
- A:HAvailability impact, high
- Dereferencing a released peer_path dentry in unix_fs_perm can cause kernel oops/panic; UAF during active socket I/O on production AppArmor-confined services (D-Bus, journald, snap apps) enables repeatable denial of service.