CVE-2026-23409In the Linux kernel, the following vulnerability has been resolved: apparmor: fix differential encoding verification Differential encoding allows loops to be created if it is abused.
Updated under an hour ago ()
Does this affect you?
It affects linux_kernel. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
In the Linux kernel, the following vulnerability has been resolved: apparmor: fix differential encoding verification Differential encoding allows loops to be created if it is abused. To prevent this the unpack should verify that a diff-encode chain terminates. Unfortunately the differential encode verification had two bugs. 1. it conflated states that had gone through check and already been marked, with states that were currently being checked and marked. This means that loops in the current chain being verified are treated as a chain that has already been verified. 2. the order bailout on already checked states compared current chain check iterators j,k instead of using the outer loop iterator i. Meaning a step backwards in states in the current chain verification was being mistaken for moving to an already verified state. Move to a double mark scheme where already verified states get a different mark, than the current chain being kept. This enables us to also drop the backwards verification check that was the cause of the second error as any already verified state is already marked.
- CVSS
- 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-835
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Analyzed
- Record last updated
- Jun 17, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
linux linux_kernel linux:linux_kernel | from 4.17.1 before 5.10.253; from 5.11 before 5.15.203; from 5.16 before 6.1.169; from 6.2 before 6.6.130; from 6.7 before 6.12.77; from 6.13 before 6.18.18; from 6.19 before 6.19.8; 4.17; and 7 more ranges | NVD |
References
- https://git.kernel.org/stable/c/0fab44285445e9012674396d5c1236a67da518e0patch
- https://git.kernel.org/stable/c/1439150cd3c411228b387ab5efca92199d2a659apatch
- https://git.kernel.org/stable/c/1ff4857fac56ac5a90ee63b24db05fa5e91a45aapatch
- https://git.kernel.org/stable/c/34fc60b125ed1d4eb002c76b0664bf0619492167patch
- https://git.kernel.org/stable/c/39440b137546a3aa383cfdabc605fb73811b6093patch
- https://git.kernel.org/stable/c/623a9d211bbbb031bb1cbdb38b23487648167f8apatch
- https://git.kernel.org/stable/c/f90e3ecd9e1ed69f1a370f866ceed1f104f3ab4apatch
- https://git.kernel.org/stable/c/ff7c73744fafe944ed9a7b2b7cf6c8d5557a3d84patch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.