CVE-2022-50859 cifs: Fix the error length of VALIDATE_NEGOTIATE_INFO message
An attacker can read uninitialized memory from the network via a malformed CIFS negotiate message, potentially leaking sensitive kernel data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-50859?
CVE-2022-50859 is a vulnerability in Linux, published on 30 Dec 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:
cifs: Fix the error length of VALIDATE_NEGOTIATE_INFO message
Commit d5c7076b772a ("smb3: add smb3.1.1 to default dialect list") extend the dialects from 3 to 4, but forget to decrease the extended length when specific the dialect, then the message length is larger than expected.
This maybe leak some info through network because not initialize the message body.
After apply this patch, the VALIDATE_NEGOTIATE_INFO message length is reduced from 28 bytes to 26 bytes.
Which versions are affected by CVE-2022-50859?
How do I fix CVE-2022-50859?
Apply the vendor's patch.
Is CVE-2022-50859 being exploited?
There is no known exploitation of CVE-2022-50859 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2022-50859, GHSA-4fwr-9cpg-j96h, UBUNTU-CVE-2022-50859.