CVE-2023-53794 cifs: fix session state check in reconnect to avoid use-after-free issue
A use-after-free vulnerability in the Linux kernel CIFS module allows attackers to potentially execute code or cause a 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-2023-53794?
CVE-2023-53794 is a critical use after free vulnerability in Linux, published on 9 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 session state check in reconnect to avoid use-after-free issue
Don't collect exiting session in smb2_reconnect_server(), because it will be released soon.
Note that the exiting session will stay in server->smb_ses_list until it complete the cifs_free_ipc() and logoff() and then delete itself from the list.
Which versions are affected by CVE-2023-53794?
How do I fix CVE-2023-53794?
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-2023-53794 being exploited?
There is no known exploitation of CVE-2023-53794 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-53794, DEBIAN-CVE-2023-53794, GHSA-x47f-6fjp-7wj4, ROOT-OS-DEBIAN-11-CVE-2023-53794, ROOT-OS-UBUNTU-2204-CVE-2023-53794, UBUNTU-CVE-2023-53794.