CVE-2025-39720 ksmbd: fix refcount leak causing resource not released
A refcount leak in the ksmbd kernel module prevents memory release, potentially leading to resource exhaustion and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-39720?
CVE-2025-39720 is a high-severity memory corruption vulnerability in Linux kernel, published on 5 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix refcount leak causing resource not released
When ksmbd_conn_releasing(opinfo->conn) returns true,the refcount was not decremented properly, causing a refcount leak that prevents the count from reaching zero and the memory from being released.
Which versions are affected by CVE-2025-39720?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-39720?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-39720 being exploited?
There is no known exploitation of CVE-2025-39720 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-66965, BELL-CVE-2025-39720, DEBIAN-CVE-2025-39720, GHSA-p63w-3x2m-q62g, ROOT-OS-DEBIAN-11-CVE-2025-39720, ROOT-OS-DEBIAN-12-CVE-2025-39720 and 4 more.