CVE-2026-31683 batman-adv: avoid OGM aggregation when skb tailroom is insufficient
A memory corruption vulnerability in the Linux kernel's batman-adv module allows attackers to cause a denial of service or potentially execute code via insufficient buffer checks during packet aggregation.
- 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-2026-31683?
CVE-2026-31683 is a high-severity memory corruption vulnerability in Linux kernel, published on 25 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:
batman-adv: avoid OGM aggregation when skb tailroom is insufficient
When OGM aggregation state is toggled at runtime, an existing forwarded packet may have been allocated with only packet_len bytes, while a later packet can still be selected for aggregation. Appending in this case can hit skb_put overflow conditions.
Reject aggregation when the target skb tailroom cannot accommodate the new packet. The caller then falls back to creating a new forward packet instead of appending.
Which versions are affected by CVE-2026-31683?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-31683?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-31683 being exploited?
There is no known exploitation of CVE-2026-31683 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-31683, DEBIAN-CVE-2026-31683, GHSA-r4hm-9crw-6g4m, ROOT-OS-DEBIAN-11-CVE-2026-31683, ROOT-OS-DEBIAN-12-CVE-2026-31683, ROOT-OS-UBUNTU-2204-CVE-2026-31683 and 2 more.