SB2026042545 - Use-after-free in Linux kernel netfilter
Published: April 25, 2026
Security Bulletin ID
SB2026042545
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-31665)
CWE-ID: CWE-416 - Use After Free
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in nft_ct_timeout_obj_destroy() when destroying timeout objects during concurrent packet processing. A local user can trigger concurrent packet processing and object destruction to cause a denial of service.
The issue arises because other CPUs may still hold RCU-protected references to the timeout object.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/070abdf1b04325b21a20a2a0c39a2208af107275
- https://git.kernel.org/stable/c/aa7cfa16f98f8ec3e6d47c34e1a8c1ae4b9b8b77
- https://git.kernel.org/stable/c/b42aca3660dc2627a29a38131597ca610dc451f9
- https://git.kernel.org/stable/c/c458fc1c278a65ad5381083121d39a479973ebed
- https://git.kernel.org/stable/c/c581e5c8f2b59158f62efe61c1a3dc36189081ff
- https://git.kernel.org/stable/c/d0983b48c10d1509fd795c155f8b1e832e1369ff
- https://git.kernel.org/stable/c/f16fe84879a5280f05ebbcea593a189ba0f3e79a
- https://git.kernel.org/stable/c/f8dca15a1b190787bbd03285304b569631160eda