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CVE-2026-72460
apparmor: check label build before no_new_privs test
Published 2026-08-15 (2 months ago) by the Linux kernel CNA. Subsystem security/apparmor. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-72460 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 | fixed | 6.1.180-1 | Update the kernel and reboot. Fixed in 6.1.180-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.100-1 | Update the kernel and reboot. Fixed in 6.12.100-1. A running kernel keeps the old code until the machine restarts. |
| 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
aa_change_profile() builds a replacement label with fn_label_build_in_scope() before the no_new_privs subset check. The build helper can fail and return NULL or an ERR_PTR, but the result was passed to aa_label_is_unconfined_subset() before the existing IS_ERR_OR_NULL() check. Reuse the existing target-label build failure handling immediately after the build. This preserves the current audit handling while preventing the subset helper from dereferencing an invalid label.
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/domain.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 below compiles the affected file into the kernels it ships.
- bookworm, trixie, forky, sidy
- y
- built into the kernel image on every flavour - only a patch removes it
- 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
- 7.1 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.13%, higher than 2.0% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- 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 |
|---|---|---|
| 4.13 | 5.10.261 | a29f06db44b4 |
| 4.13 | 5.15.212 | cfc224866530 |
| 4.13 | 6.1.178 | 31cb109db5e6 |
| 4.13 | 6.6.145 | b7c45c05a396 |
| 4.13 | 6.12.97 | d84bb195d208 |
| 4.13 | 6.18.40 | d82160132345 |
| 4.13 | 7.1.5 | ec926b2a351e |
| 4.13 | 7.2 | a58cafd38b46 |
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
- The flaw is reached only through a local write to /proc/self/attr/current or /proc/self/attr/exec (changeprofile/exec), which flows through proc_pid_attr_write and the AppArmor setprocattr hook into aa_change_profile(); there is no network, adjacent-radio, or physical-device entry point.
- AC:LAttack complexity, low
- Once a confined task with policy-granted changeprofile and PR_SET_NO_NEW_PRIVS calls the interface, fn_label_build_in_scope() failure (e.g., GFP_KERNEL ENOMEM from memory pressure) is reliably attacker-influenced and immediately triggers the invalid dereference without races or victim-dependent timing.
- PR:LPrivileges required, low
- Exploitation requires a local unprivileged process confined by AppArmor whose policy permits changeprofile/onexec to the requested target; prctl(PR_SET_NO_NEW_PRIVS) is self-settable and does not require real root or init-namespace capabilities.
- UI:NUser interaction, none
- The attacker triggers the bug by writing to their own process attribute file; no separate victim action such as opening a file, mounting a filesystem, or clicking a link is required.
- S:UScope, unchanged
- The vulnerable AppArmor kernel code and the resulting kernel oops/panic affect the same OS security authority; this is not a VM escape, IOMMU bypass, or cross-authority sandbox breakout as defined by CVSS scope.
- C:HConfidentiality impact, high
- aa_label_is_unconfined_subset() dereferences the failed label pointer (NULL or ERR_PTR) to read aa_label fields such as size/vec; ERR_PTR values are non-NULL kernel-range addresses, so the fault path includes an invalid kernel-memory read that can leak data before oops under worst-case layout.
- I:NIntegrity impact, none
- The bug performs invalid reads through a bad label pointer and does not write memory, corrupt adjacent objects, or complete an unauthorized aa_replace_current_label(); failed builds are still rejected later, so integrity impact is limited to the read-side fault rather than modification or code execution.
- A:HAvailability impact, high
- Dereferencing NULL or ERR_PTR labels in aa_label_is_unconfined_subset() causes a kernel BUG/oops/panic, yielding host-wide denial of service on AppArmor-enabled systems and repeatable crashes from the same procattr write.