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: smb: client: fix race with concurrent opens in rename(2) (CVE-2025-39825) * 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
This Red Hat security advisory (RHSA-2025:23425) addresses three kernel vulnerabilities in Red Hat Enterprise Linux 8.6. CVE-2025-39825 fixes a race condition in the SMB client related to concurrent file opens during the rename(2) system call. CVE-2025-39955 and CVE-2025-40186 address TCP stack issues involving the handling of tcp_sk(sk)->fastopen_rsk in tcp_disconnect() and the improper invocation of reqsk_fastopen_remove() in tcp_conn_request(), respectively. These fixes prevent potential kernel-level race conditions and improper TCP socket state handling. The advisory requires applying updated kernel packages and rebooting the system for the fixes to take effect.
Potential Impact
The vulnerabilities impact the Linux kernel's SMB client and TCP networking stack, potentially leading to race conditions and improper TCP socket state management. This could affect system stability or security in scenarios involving concurrent file operations over SMB and TCP connection handling. The advisory rates the impact as important/high severity but does not specify exact exploitation details or CVSS scores. No known exploits in the wild have been reported at this time.
Mitigation Recommendations
A security update for the kernel packages is available from Red Hat for Red Hat Enterprise Linux 8.6 variants. Applying the update and rebooting the system is required to remediate these vulnerabilities. Refer to Red Hat's official advisory RHSA-2025:23425 and article https://access.redhat.com/articles/11258 for detailed update instructions. No additional mitigation steps are indicated beyond applying the official patch and rebooting.
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: smb: client: fix race with concurrent opens in rename(2) (CVE-2025-39825) * 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
This Red Hat security advisory (RHSA-2025:23425) addresses three kernel vulnerabilities in Red Hat Enterprise Linux 8.6. CVE-2025-39825 fixes a race condition in the SMB client related to concurrent file opens during the rename(2) system call. CVE-2025-39955 and CVE-2025-40186 address TCP stack issues involving the handling of tcp_sk(sk)->fastopen_rsk in tcp_disconnect() and the improper invocation of reqsk_fastopen_remove() in tcp_conn_request(), respectively. These fixes prevent potential kernel-level race conditions and improper TCP socket state handling. The advisory requires applying updated kernel packages and rebooting the system for the fixes to take effect.
Potential Impact
The vulnerabilities impact the Linux kernel's SMB client and TCP networking stack, potentially leading to race conditions and improper TCP socket state management. This could affect system stability or security in scenarios involving concurrent file operations over SMB and TCP connection handling. The advisory rates the impact as important/high severity but does not specify exact exploitation details or CVSS scores. No known exploits in the wild have been reported at this time.
Mitigation Recommendations
A security update for the kernel packages is available from Red Hat for Red Hat Enterprise Linux 8.6 variants. Applying the update and rebooting the system is required to remediate these vulnerabilities. Refer to Red Hat's official advisory RHSA-2025:23425 and article https://access.redhat.com/articles/11258 for detailed update instructions. No additional mitigation steps are indicated beyond applying the official patch and rebooting.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2025:23425
- Cve Count
- 3
- Additional Cves
- ["CVE-2025-39955","CVE-2025-40186"]
- Cvss Version
- null
Threat ID: 6a419ca827e9c79719ab7a69
Added to database: 06/28/2026, 22:14:00 UTC
Last enriched: 06/28/2026, 22:16:09 UTC
Last updated: 07/02/2026, 20:51:16 UTC
Views: 2
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