CVE-2026-23416 mm/mseal: update VMA end correctly on merge
Incorrect VMA end calculation during memory sealing merges can lead to inconsistent memory state, requiring a kernel patch.
- 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-2026-23416?
CVE-2026-23416 is a medium-severity vulnerability in Linux kernel, published on 2 Apr 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:
mm/mseal: update VMA end correctly on merge
Previously we stored the end of the current VMA in curr_end, and then upon iterating to the next VMA updated curr_start to curr_end to advance to the next VMA.
However, this doesn't take into account the fact that a VMA might be updated due to a merge by vma_modify_flags(), which can result in curr_end being stale and thus, upon setting curr_start to curr_end, ending up with an incorrect curr_start on the next iteration.
Resolve the issue by setting curr_end to vma->vm_end unconditionally to ensure this value remains updated should this occur.
While we're here, eliminate this entire class of bug by simply setting const curr_[start/end] to be clamped to the input range and VMAs, which also happens to simplify the logic.
Which versions are affected by CVE-2026-23416?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-23416?
Apply the vendor's patch.
Is CVE-2026-23416 being exploited?
There is no known exploitation of CVE-2026-23416 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-2026-23416, DEBIAN-CVE-2026-23416, GHSA-h9cv-r6cj-w8vj, UBUNTU-CVE-2026-23416.