SB2026081212 - Red Hat Enterprise Linux 9 update for kernel
Published: August 12, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 vulnerabilities.
1) Out-of-bounds read (CVE-ID: CVE-2026-43112)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 6.8 [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]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to out-of-bounds read in cifs_sanitize_prepath when parsing path strings containing only delimiters or no path content. A local user can supply a crafted path string to cause a denial of service.
The issue can be triggered by an empty string or a string such as "/".
2) Improper privilege management (CVE-ID: CVE-2025-54518)
CWE-ID: CWE-269 - Improper Privilege Management
CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to escalate privileges.
The vulnerability exists due to improper privilege management in x86 CPU opcode cache handling when executing code on affected AMD Fam17h CPUs. A local user can execute code to escalate privileges.
The issue can permit escalation across privilege boundaries including userspace to kernel and guest to host, and only AMD Fam17h CPUs based on the Zen2 microarchitecture are believed to be affected.
3) Use-after-free (CVE-ID: CVE-2026-53264)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in the net/sched action lifecycle handling in act_api when NEWTFILTER and DELFILTER are run concurrently. A local user can trigger concurrent filter operations to cause a denial of service.
The issue arises from a race between action lookup and action deletion under RCU-protected access.
Remediation
Install update from vendor's website.