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: wifi: cfg80211: fix use-after-free in cmp_bss() (CVE-2025-39864) * kernel: tcp: Clear tcp_sk(sk)->fastopen_rsk in tcp_disconnect() (CVE-2025-39955) * kernel: tcp: Don't call reqsk_fastopen_remove() in tcp_conn_request() (CVE-2025-40186) 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
The advisory covers three kernel vulnerabilities: a use-after-free in the wifi cfg80211 subsystem (CVE-2025-39864), and two TCP stack issues related to clearing and removing fastopen_rsk references improperly (CVE-2025-39955 and CVE-2025-40186). These flaws could potentially lead to memory corruption or unstable TCP connection handling. Red Hat has released updated kernel packages for Red Hat Enterprise Linux 9.4 Extended Update Support that address these vulnerabilities. The update requires a system reboot to take effect. No CVSS scores are provided in the advisory, but the security impact is rated as important by Red Hat Product Security.
Potential Impact
The vulnerabilities affect the Linux kernel core components, potentially allowing memory corruption (use-after-free) and improper TCP connection state handling. This could impact system stability or security depending on exploitation, though no known exploits in the wild have been reported. The issues affect network-related kernel functionality, which is critical for system operation.
Mitigation Recommendations
Red Hat has released patched kernel packages for Red Hat Enterprise Linux 9.4 Extended Update Support that fix these vulnerabilities. Users should apply the available kernel update as described in the Red Hat advisory (https://access.redhat.com/articles/11258) and reboot affected systems to ensure the fixes take effect. No additional mitigation steps 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: wifi: cfg80211: fix use-after-free in cmp_bss() (CVE-2025-39864) * kernel: tcp: Clear tcp_sk(sk)->fastopen_rsk in tcp_disconnect() (CVE-2025-39955) * kernel: tcp: Don't call reqsk_fastopen_remove() in tcp_conn_request() (CVE-2025-40186) 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
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The advisory covers three kernel vulnerabilities: a use-after-free in the wifi cfg80211 subsystem (CVE-2025-39864), and two TCP stack issues related to clearing and removing fastopen_rsk references improperly (CVE-2025-39955 and CVE-2025-40186). These flaws could potentially lead to memory corruption or unstable TCP connection handling. Red Hat has released updated kernel packages for Red Hat Enterprise Linux 9.4 Extended Update Support that address these vulnerabilities. The update requires a system reboot to take effect. No CVSS scores are provided in the advisory, but the security impact is rated as important by Red Hat Product Security.
Potential Impact
The vulnerabilities affect the Linux kernel core components, potentially allowing memory corruption (use-after-free) and improper TCP connection state handling. This could impact system stability or security depending on exploitation, though no known exploits in the wild have been reported. The issues affect network-related kernel functionality, which is critical for system operation.
Mitigation Recommendations
Red Hat has released patched kernel packages for Red Hat Enterprise Linux 9.4 Extended Update Support that fix these vulnerabilities. Users should apply the available kernel update as described in the Red Hat advisory (https://access.redhat.com/articles/11258) and reboot affected systems to ensure the fixes take effect. No additional mitigation steps 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-2025:23450
- Cve Count
- 3
- Additional Cves
- ["CVE-2025-39955","CVE-2025-40186"]
- Cvss Version
- null
Threat ID: 6a3da1d84853345fc1827dbf
Added to database: 06/25/2026, 21:47:04 UTC
Last enriched: 06/25/2026, 22:17:45 UTC
Last updated: 07/02/2026, 08:51:16 UTC
Views: 4
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