CVE-2026-52914 batman-adv: fix fragment reassembly length accounting
A local attacker can cause a denial of service in the Linux kernel by exploiting an integer overflow in batman-adv fragment reassembly length accounting.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-52914?
CVE-2026-52914 is a critical vulnerability in Linux kernel, published on 24 Jun 2026. 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:
batman-adv: fix fragment reassembly length accounting
batman-adv keeps a running payload length for queued fragments and uses it to validate a fragment chain before reassembly.
That accounting currently allows the accumulated fragment length to be truncated during updates. As a result, malformed fragment chains can bypass the intended validation and drive reassembly with inconsistent length state, leading to a local denial of service.
Fix the accounting by storing the accumulated length in a length-typed field and rejecting update overflows before the existing validation logic runs.
The fix was verified against the original reproducer and against valid fragment reassembly paths.
Which versions are affected by CVE-2026-52914?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-52914?
Apply the vendor's patch.
Is CVE-2026-52914 being exploited?
There is no known exploitation of CVE-2026-52914 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-90821, BELL-CVE-2026-52914, DEBIAN-CVE-2026-52914, GHSA-637x-w8p5-96wm, ROOT-OS-DEBIAN-11-CVE-2026-52914, ROOT-OS-DEBIAN-12-CVE-2026-52914 and 3 more.