Summary
In the Linux kernel, the following vulnerability has been resolved: fs/smb: Fix inconsistent...
In the Linux kernel, the following vulnerability has been resolved:
fs/smb: Fix inconsistent refcnt update
A possible inconsistent update of refcount was identified in smb2_compound_op.
Such inconsistent update could lead to possible resource leaks.
Why it is a possible bug:
- In the comment section of the function, it clearly states that the
reference tocfileshould be dropped after calling this function. - Every control flow path would check and drop the reference to
cfile, except the patched one. - Existing callers would not handle refcount update of
cfileif
-ENOMEM is returned.
To fix the bug, an extra goto label "out" is added, to make sure that the
cleanup logic would always be respected. As the problem is caused by the
allocation failure of vars, the cleanup logic between label "finished"
and "out" can be safely ignored. According to the definition of functionis_replayable_error, the error code of "-ENOMEM" is not recoverable.
Therefore, the replay logic also gets ignored.
Impact
CVE-2025-39819 has a CVSS score of 5.5 (Medium). The vector is requires local access, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2025-39819? CVE-2025-39819 is a medium-severity security vulnerability. No fixed version is listed yet.
- How severe is CVE-2025-39819? CVE-2025-39819 has a CVSS score of 5.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Is there a fix for CVE-2025-39819? No fixed version is listed for CVE-2025-39819 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2025-39819 exploitable, and should I be worried? Whether CVE-2025-39819 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-39819 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.