Medium 5.5Published May 27, 2026

CVE-2026-45884apparmor: avoid per-cpu hold underflow in aa_get_buffer

Updated under an hour ago (Oct 27, 2026, 12:50 AM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: apparmor: avoid per-cpu hold underflow in aa_get_buffer When aa_get_buffer() pulls from the per-cpu list it unconditionally decrements cache->hold. If hold reaches 0 while count is still non-zero, the unsigned decrement wraps to UINT_MAX. This keeps hold non-zero for a very long time, so aa_put_buffer() never returns buffers to the global list, which can starve other CPUs and force repeated kmalloc(aa_g_path_max) allocations. Guard the decrement so hold never underflows.

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): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: May 27, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from ea9bae12d02819556db63348db8bd8441eb316f2 before 202824a1f89a9786c20a3d646a7c88d223abb1b2; from ea9bae12d02819556db63348db8bd8441eb316f2 before 80c334acc6d0bee8605a358a33e69b4aea1ffb92; from ea9bae12d02819556db63348db8bd8441eb316f2 before 4bcddd0f6b2e52b4c7b520e4d36a115caf5b7169; from ea9bae12d02819556db63348db8bd8441eb316f2 before 640cf2f09575c9dc344b3f7be2498d31e3923ead	CNA record
linux linux_kernel linux:linux_kernel	from 6.7 before 6.12.75; from 6.13 before 6.18.14; from 6.19 before 6.19.4	NVD

References

References

https://git.kernel.org/stable/c/202824a1f89a9786c20a3d646a7c88d223abb1b2	patch
https://git.kernel.org/stable/c/80c334acc6d0bee8605a358a33e69b4aea1ffb92	patch
https://git.kernel.org/stable/c/4bcddd0f6b2e52b4c7b520e4d36a115caf5b7169	patch
https://git.kernel.org/stable/c/640cf2f09575c9dc344b3f7be2498d31e3923ead	patch

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.