SB20260507280 - Use-after-free in Linux kernel netfilter
Published: May 7, 2026
Security Bulletin ID
SB20260507280
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-2026-43084)
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 nfnetlink_queue when processing queue verdicts in parallel. A local user can send crafted netfilter queue verdict messages to trigger a kernel crash.
The issue occurs because an nf_queue_entry may be freed on one CPU while still being encountered by another CPU walking the shared list.
Remediation
Install update from vendor's website.