SB2026071462 - Red Hat Enterprise Linux 8 update for kernel-rt
Published: July 14, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) NULL pointer dereference (CVE-ID: CVE-2026-46086)
CWE-ID: CWE-476 - NULL Pointer Dereference
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 null pointer dereference in br_fdb_fillbuf() when reading bridge forwarding database entries through the brforward_read() sysfs path during a concurrent local FDB update. A local user can trigger concurrent access to cause a denial of service.
The issue arises because RCU readers can observe inconsistent values of f->dst across a check and a later dereference.
2) Use-after-free (CVE-ID: CVE-2026-46116)
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 __xfrm_state_delete when deleting xfrm_state list entries during xfrm_state lifecycle handling. A local user can trigger repeated deletion of the same xfrm_state object to cause a denial of service.
The issue was reproduced under syzkaller load during network namespace cleanup in the xfrm subsystem.
Remediation
Install update from vendor's website.