CVE-2023-32255 Kernel: memory leak via ksmbd session setup request with unknown ntlmssp message type
A memory leak in the Linux kernel's ksmbd component allows remote attackers to cause resource exhaustion and denial of service via crafted session setup requests.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-32255?
CVE-2023-32255 is a medium-severity denial of service vulnerability in Red Hat Enterprise Linux 10, published on 2 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 memory leak can occur if a client sends a session setup request with an unknown NTLMSSP message type, potentially leading to resource exhaustion.
Weakness: CWE-772
Which versions are affected by CVE-2023-32255?
How do I fix CVE-2023-32255?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-32255 being exploited?
There is no known exploitation of CVE-2023-32255 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2023-32255, GHSA-3hjh-cjx8-8c83, ROOT-OS-DEBIAN-11-CVE-2023-32255, UBUNTU-CVE-2023-32255.