CVE-2025-38527
A flaw in the Linux kernel's SMB client allows for a 'use-after-free' error during the unmounting process. This happens when a race condition occurs while the system is cleaning up files, causing the system to try to use memory that has already been released.
An official fix is available, so this entry is kept for 30 days and then removed automatically.
Who is affected
Users running the Linux kernel, specifically versions such as 5.1 or 6.16, including those on Debian 11.0.
Real-world impact
An attacker could potentially exploit this race condition to cause a system crash or execute arbitrary code, leading to a total loss of confidentiality, integrity, and availability.
Why this severity
The critical score reflects that this vulnerability can be exploited remotely over a network without requiring any user interaction or special privileges, potentially resulting in full system compromise.
What to do about it
- 01Update the Linux kernel to a version that includes the fix for cifs_oplock_break.
NVD-referenced vendor advisory
Timeline
- Aug 16, 2025 · Aug 16, 2025PublishedDisclosed and added to the National Vulnerability Database.
- Jul 30, 2026 · 7d agoAdvisory updatedThe NVD record was last revised.
- Jul 30, 2026 · 6d agoOfficial fix availableA vendor patch or mitigation now exists — see the remediation steps above.
How it’s attacked
References & advisories
- git.kernel.org/stable/c/09bce2138a30ef10d8…patch
- git.kernel.org/stable/c/0a4eec84d4d2c4085d…patch
- git.kernel.org/stable/c/2baaf5bbab2ac474c4…patch
- git.kernel.org/stable/c/4256a483fe58af66a4…patch
- git.kernel.org/stable/c/705c79101ccf9edea5…patch
- git.kernel.org/stable/c/da11bd4b697b393a20…patch
- lists.debian.org/debian-lts-announce/2025/10…mailing listthird party advisory