CVE-2026-23410: apparmor: fix race on rawdata dereference
In the Linux kernel, the following vulnerability has been resolved:
apparmor: fix race on rawdata dereference
There is a race condition that leads to a use-after-free situation:
because the rawdata inodes are not refcounted, an attacker can start
open()ing one of the rawdata files, and at the same time remove the
last reference to this rawdata (by removing the corresponding profile,
for example), which frees its struct aa_loaddata; as a result, when
seq_rawdata_open() is reached, i_private is a dangling pointer and
freed memory is accessed.
The rawdata inodes weren't refcounted to avoid a circular refcount and
were supposed to be held by the profile rawdata reference. However
during profile removal there is a window where the vfs and profile
destruction race, resulting in the use after free.
Fix this by moving to a double refcount scheme. Where the profile
refcount on rawdata is used to break the circular dependency. Allowing
for freeing of the rawdata once all inode references to the rawdata
are put.
Security readout for executives and security teams
Plain-English summary
A Linux AppArmor race can make the kernel access memory after it has been freed. A local, low-privileged attacker could potentially crash or compromise an affected system without user interaction. The supplied CVSS score is 7.8 (high).
Executive priority
Treat this as high-priority kernel maintenance, especially for shared or externally accessible systems offering local accounts. It is not presented as an internet-reachable flaw, and active exploitation is unconfirmed, but successful local exploitation could have system-wide consequences.
Technical view
Rawdata inodes lacked independent reference counting. Concurrently opening a rawdata file while its associated profile data is destroyed can leave inode i_private pointing to freed aa_loaddata memory before seq_rawdata_open dereferences it. The cited kernel fix introduces a double-reference-counting scheme to control inode and profile lifetimes.
Likely exposure
Exposure is most likely on Linux systems using AppArmor and running affected kernel builds. The bundle lists versions from 4.13 through 7.0, including several branch-specific releases, but does not clearly express affected ranges. Distribution package mappings therefore require vendor confirmation.
Exploitation context
The CVSS vector describes local access, low attack complexity, low privileges, and no user interaction, with potentially high confidentiality, integrity, and availability impact. The CVE is not listed as KEV, and the supplied sources provide no evidence of active or public exploitation.
Researcher notes
The vulnerable lifetime transition concerns AppArmor rawdata inode references and profile-owned aa_loaddata. Assessment should examine whether reachable rawdata files can race with removal of the final profile reference. The bundle supplies eight stable commits but no explicit commit-to-release mapping or exploit evidence.
Mitigation direction
Install the vendor kernel update containing the appropriate cited stable fix for your maintained branch.
Prioritize multi-user systems and hosts where untrusted users can obtain local accounts.
Restrict unnecessary local access until affected package mappings and updates are confirmed.
Consult distribution guidance because the supplied version data does not clearly define branch ranges.
Validation and detection
Inventory kernel package versions and identify systems where AppArmor is enabled.
Compare each distribution build against vendor advisories and the cited stable kernel fixes.
After updating, verify the corrected kernel is installed and actively booted.
Confirm vulnerability scanners use distribution package status rather than upstream version strings alone.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Potential ATT&CK relevance
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CVE-2026-23410 mapping review
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1CVSS vectors
3Timeline events
0ADP providers
9Source links
CVSS vector scores
1 official score
We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.