SB2026102651 - Red Hat Enterprise Linux 9 update for kernel
Published: October 26, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) Protection mechanism failure (CVE-ID: CVE-2026-64508)
CWE-ID: CWE-693 - Protection Mechanism Failure
CVSSv4: 2.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to bypass branch prediction isolation for reused BPF JIT memory.
The vulnerability exists due to improper isolation of indirect branch predictor state in the BPF JIT allocator when reusing JIT memory for newly written programs. A remote attacker can load and free BPF programs to bypass branch prediction isolation for reused BPF JIT memory.
Allocations larger than a pack are not covered by this condition, and the described attack surface is limited to cBPF programs that fit within pack size constraints.
2) Observable discrepancy (CVE-ID: CVE-2026-64507)
CWE-ID: CWE-203 - Observable discrepancy
CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to disclose sensitive information.
The vulnerability exists due to improper protection against speculative execution in BPF JIT memory reuse on x86 systems when reusing JIT-compiled BPF memory under Spectre-v2 conditions. A local user can trigger BPF JIT allocation reuse to disclose sensitive information.
Only systems with BPF-JIT enabled are affected.
Remediation
Install update from vendor's website.