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 Red Hat security advisory (RHSA-2026:9643) fixes four kernel vulnerabilities affecting Red Hat Enterprise Linux 8.4. The fixes address use-after-free vulnerabilities in the smc subsystem (__pnet_find_base_ndev(), CVE-2025-40064), improvements in smc_clc_prfx_match() (CVE-2025-40168), safer pointer usage in net/sched cls_u32 (CVE-2026-23204), and a use-after-free in nf_tables_addchain() that could lead to privilege escalation or denial of service (CVE-2026-23231). The advisory rates the overall impact as moderate and requires a system reboot after applying the updates.
Potential Impact
The vulnerabilities could allow an attacker to cause denial of service or escalate privileges on affected systems running Red Hat Enterprise Linux 8.4. The use-after-free bugs in kernel components may lead to memory corruption, potentially compromising system stability or security. No known exploits in the wild have been reported at this time.
Mitigation Recommendations
Red Hat has released official patches for these vulnerabilities as part of the kernel update for Red Hat Enterprise Linux 8.4. Users should apply the update promptly and reboot their systems to ensure the fixes take effect. For detailed update instructions, refer to Red Hat's advisory at https://access.redhat.com/articles/11258. No additional mitigations are indicated by the vendor.
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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This Red Hat security advisory (RHSA-2026:9643) fixes four kernel vulnerabilities affecting Red Hat Enterprise Linux 8.4. The fixes address use-after-free vulnerabilities in the smc subsystem (__pnet_find_base_ndev(), CVE-2025-40064), improvements in smc_clc_prfx_match() (CVE-2025-40168), safer pointer usage in net/sched cls_u32 (CVE-2026-23204), and a use-after-free in nf_tables_addchain() that could lead to privilege escalation or denial of service (CVE-2026-23231). The advisory rates the overall impact as moderate and requires a system reboot after applying the updates.
Potential Impact
The vulnerabilities could allow an attacker to cause denial of service or escalate privileges on affected systems running Red Hat Enterprise Linux 8.4. The use-after-free bugs in kernel components may lead to memory corruption, potentially compromising system stability or security. No known exploits in the wild have been reported at this time.
Mitigation Recommendations
Red Hat has released official patches for these vulnerabilities as part of the kernel update for Red Hat Enterprise Linux 8.4. Users should apply the update promptly and reboot their systems to ensure the fixes take effect. For detailed update instructions, refer to Red Hat's advisory at https://access.redhat.com/articles/11258. No additional mitigations are indicated by the vendor.
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
- null
Threat ID: 6a27e9fd8dd33fbd8517cf95
Added to database: 6/9/2026, 10:25:01 AM
Last enriched: 6/9/2026, 10:27:34 AM
Last updated: 6/10/2026, 5:02:37 AM
Views: 7
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