CVE-2025-40103

CVE-2025-40103 is a security vulnerability that is still awaiting full analysis and scoring. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: Fix refcount leak for cifs_sb_tlink Fix three refcount inconsistency issues related to `cifs_sb_tlink`. Comments for `cifs_sb_tlink` state that `cifs_put_tlink()` needs to be called after successful calls to `cifs_sb_tlink()`. Three calls fail to update refcount accordingly, leading to possible resource leaks.

Frequently asked questions

What is CVE-2025-40103?
In the Linux kernel, the following vulnerability has been resolved: smb: client: Fix refcount leak for cifs_sb_tlink Fix three refcount inconsistency issues related to `cifs_sb_tlink`. Comments for `cifs_sb_tlink` state that `cifs_put_tlink()` needs to be called after successful calls to `cifs_sb_tlink()`. Three calls fail to update refcount accordingly, leading to possible resource leaks.
Is CVE-2025-40103 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-40103?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-40103 have an EU (EUVD) identifier?
Yes. CVE-2025-40103 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-36975.
When was CVE-2025-40103 published?
CVE-2025-40103 was published on 2025-10-30 and last updated on 2026-06-17.

References