Red Hat Security Advisory: kernel security update
The kernel packages contain the Linux kernel, the core of any Linux operating system. Security Fix(es): * kernel: smc: Fix use-after-free in __pnet_find_base_ndev() (CVE-2025-40064) * kernel: smc: Use __sk_dst_get() and dst_dev_rcu() in smc_clc_prfx_match() (CVE-2025-40168) * kernel: net/sched: cls_u32: use skb_header_pointer_careful() (CVE-2026-23204) * kernel: kernel: Privilege escalation or denial of service via use-after-free in nf_tables_addchain() (CVE-2026-23231) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
AI Analysis
Technical Summary
This advisory addresses four security vulnerabilities in the Linux kernel packages for Red Hat Enterprise Linux 8.4. The issues include use-after-free bugs in the smc component (__pnet_find_base_ndev(), smc_clc_prfx_match()) and nf_tables_addchain(), as well as a memory handling issue in net/sched's cls_u32 component. These flaws could lead to privilege escalation or denial of service. Red Hat has released updated kernel packages that fix these vulnerabilities. The advisory references CVE-2025-40064, CVE-2025-40168, CVE-2026-23204, and CVE-2026-23231. The update requires a system reboot to take effect.
Potential Impact
The vulnerabilities could allow an attacker to escalate privileges or cause denial of service on affected systems running Red Hat Enterprise Linux 8.4. The issues stem from use-after-free and improper memory handling in kernel components, which could be exploited to compromise system integrity or availability. No known exploits in the wild have been reported at this time.
Mitigation Recommendations
Red Hat has released updated kernel packages that address these vulnerabilities. Users of Red Hat Enterprise Linux 8.4 should apply the security update as described in the Red Hat advisory RHSA-2026:9643 and reboot their systems to ensure the fixes take effect. Patch status is confirmed as official-fix by Red Hat Product Security.
Red Hat Security Advisory: kernel security update
Description
The kernel packages contain the Linux kernel, the core of any Linux operating system. Security Fix(es): * kernel: smc: Fix use-after-free in __pnet_find_base_ndev() (CVE-2025-40064) * kernel: smc: Use __sk_dst_get() and dst_dev_rcu() in smc_clc_prfx_match() (CVE-2025-40168) * kernel: net/sched: cls_u32: use skb_header_pointer_careful() (CVE-2026-23204) * kernel: kernel: Privilege escalation or denial of service via use-after-free in nf_tables_addchain() (CVE-2026-23231) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Affected software
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This advisory addresses four security vulnerabilities in the Linux kernel packages for Red Hat Enterprise Linux 8.4. The issues include use-after-free bugs in the smc component (__pnet_find_base_ndev(), smc_clc_prfx_match()) and nf_tables_addchain(), as well as a memory handling issue in net/sched's cls_u32 component. These flaws could lead to privilege escalation or denial of service. Red Hat has released updated kernel packages that fix these vulnerabilities. The advisory references CVE-2025-40064, CVE-2025-40168, CVE-2026-23204, and CVE-2026-23231. The update requires a system reboot to take effect.
Potential Impact
The vulnerabilities could allow an attacker to escalate privileges or cause denial of service on affected systems running Red Hat Enterprise Linux 8.4. The issues stem from use-after-free and improper memory handling in kernel components, which could be exploited to compromise system integrity or availability. No known exploits in the wild have been reported at this time.
Mitigation Recommendations
Red Hat has released updated kernel packages that address these vulnerabilities. Users of Red Hat Enterprise Linux 8.4 should apply the security update as described in the Red Hat advisory RHSA-2026:9643 and reboot their systems to ensure the fixes take effect. Patch status is confirmed as official-fix by Red Hat Product Security.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2026:9643
- Cve Count
- 4
- Additional Cves
- ["CVE-2025-40168","CVE-2026-23204","CVE-2026-23231"]
- Cvss Version
- 3.1
Threat ID: 6a27e9fd8dd33fbd8517cf95
Added to database: 06/09/2026, 10:25:01 UTC
Last enriched: 07/12/2026, 10:19:50 UTC
Last updated: 09/10/2026, 19:36:50 UTC
Views: 551
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