SB20260422175 - Red Hat Enterprise Linux 8 update for kernel

Description

This security bulletin contains information about 4 vulnerabilities.

1) Use-after-free (CVE-ID: CVE-2025-40064)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 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/E:U/U:Clear

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a use-after-free error within the smc_pnet_find_ism_by_pnetid() function in net/smc/smc_pnet.c. A local user can escalate privileges on the system.

2) Use-after-free (CVE-ID: CVE-2025-40168)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 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/E:U/U:Clear

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a use-after-free error within the smc_clc_prfx_match6_rcu() function in net/smc/smc_clc.c. A local user can escalate privileges on the system.

3) Out-of-bounds read (CVE-ID: CVE-2026-23204)

CWE-ID: CWE-125 - Out-of-bounds read

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 perform a denial of service (DoS) attack.

The vulnerability exists due to an out-of-bounds read error within the u32_classify() function in net/sched/cls_u32.c. A local user can perform a denial of service (DoS) attack.

4) Use-after-free (CVE-ID: CVE-2026-23231)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 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/E:U/U:Clear

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a use-after-free error within the nf_tables_addchain() function in net/netfilter/nf_tables_api.c. A local user can escalate privileges on the system.

Remediation

Install update from vendor's website.

References

• https://access.redhat.com/errata/RHSA-2026:9514