CVE-2026-43074 eventpoll: defer struct eventpoll free to RCU grace period
A use-after-free vulnerability in the Linux kernel's eventpoll subsystem allows attackers to potentially execute code or escalate privileges via concurrent thread manipulation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-43074?
CVE-2026-43074 is a high-severity use after free vulnerability in Linux kernel, published on 6 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
eventpoll: defer struct eventpoll free to RCU grace period
In certain situations, ep_free() in eventpoll.c will kfree the epi->ep eventpoll struct while it still being used by another concurrent thread. Defer the kfree() to an RCU callback to prevent UAF.
Which versions are affected by CVE-2026-43074?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43074?
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-2026-43074 being exploited?
There is no known exploitation of CVE-2026-43074 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-43074, DEBIAN-CVE-2026-43074, GHSA-4j6h-qqh4-vpw7, ROOT-OS-UBUNTU-2204-CVE-2026-43074, ROOT-OS-UBUNTU-2404-CVE-2026-43074, UBUNTU-CVE-2026-43074.