CVE-2026-45899 ext4: drop extent cache when splitting extent fails
A flaw in the Linux kernel ext4 filesystem allows stale extent entries to remain after a failed split, potentially causing denial of service.
- 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-2026-45899?
CVE-2026-45899 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 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:
ext4: drop extent cache when splitting extent fails
When the split extent fails, we might leave some extents still being processed and return an error directly, which will result in stale extent entries remaining in the extent status tree. So drop all of the remaining potentially stale extents if the splitting fails.
Which versions are affected by CVE-2026-45899?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-45899?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-45899 being exploited?
There is no known exploitation of CVE-2026-45899 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-88668, BELL-CVE-2026-45899, DEBIAN-CVE-2026-45899, GHSA-fm97-7qpp-598c, ROOT-OS-DEBIAN-11-CVE-2026-45899, ROOT-OS-DEBIAN-12-CVE-2026-45899 and 3 more.