CVE-2026-43239 smb: client: prevent races in ->query_interfaces()
A race condition in the Linux kernel SMB client allows concurrent interface updates, potentially leading to inconsistent state or undefined behavior.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-43239?
CVE-2026-43239 is a high-severity vulnerability in Linux kernel, published on 6 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
In the Linux kernel, the following vulnerability has been resolved:
smb: client: prevent races in ->query_interfaces()
It was possible for two query interface works to be concurrently trying to update the interfaces.
Prevent this by checking and updating iface_last_update under iface_lock.
Weakness: CWE-362
Which versions are affected by CVE-2026-43239?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43239?
Apply the vendor's patch.
Is CVE-2026-43239 being exploited?
There is no known exploitation of CVE-2026-43239 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-43239, DEBIAN-CVE-2026-43239, GHSA-5w3w-mcf7-v883, ROOT-OS-DEBIAN-11-CVE-2026-43239, ROOT-OS-DEBIAN-12-CVE-2026-43239, ROOT-OS-UBUNTU-2204-CVE-2026-43239 and 2 more.