CVE-2023-32256 Kernel: ksmbd race issue from smb2 close and logoff with multichannel
A race condition in the Linux kernel's ksmbd component allows attackers to trigger a use-after-free, potentially leading to code execution or privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-32256?
CVE-2023-32256 is a high-severity use after free vulnerability in Red Hat Enterprise Linux 10, published on 1 Aug 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A flaw was found in the Linux kernel's ksmbd component. A race condition between smb2 close operation and logoff in multichannel connections could result in a use-after-free issue.
Weakness: CWE-421
Which versions are affected by CVE-2023-32256?
How do I fix CVE-2023-32256?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2023-32256 being exploited?
There is no known exploitation of CVE-2023-32256 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2023-32256, GHSA-fmp3-xxcc-559c, ROOT-OS-DEBIAN-11-CVE-2023-32256, UBUNTU-CVE-2023-32256.