CVE-2026-45884

MEDIUMCVSS 5.5/10EPSS 0.15%

Last modified

CVE-2026-45884 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. 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. EPSS estimates a 0.15% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1
5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability
0.15%

5.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
LinuxLinux Kernel>= 6.7, < 6.12.75
LinuxLinux Kernel>= 6.13, < 6.18.14
LinuxLinux Kernel>= 6.19, < 6.19.4

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-45884?
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.
How severe is CVE-2026-45884?
CVE-2026-45884 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.15% probability of exploitation in the next 30 days.
How do I fix CVE-2026-45884?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-45884?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST