CVE-2026-72234 batman-adv: access unicast_ttvn skb->data only after skb realloc
A use-after-free vulnerability in the batman-adv kernel module allows attackers to potentially execute code or escalate privileges via crafted network packets.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-72234?
CVE-2026-72234 is a critical use after free vulnerability in Linux, published on 15 Aug 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: access unicast_ttvn skb->data only after skb realloc
The pskb_may_pull() called by batadv_get_vid() could reallocate the buffer behind the skb. Variables which were pointing to the old buffer need to be reassigned to avoid an use-after-free.
This was done correctly for the ethernet header but missed for the unicast_packet pointer.
Which versions are affected by CVE-2026-72234?
How do I fix CVE-2026-72234?
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-2026-72234 being exploited?
There is no known exploitation of CVE-2026-72234 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72234, DEBIAN-CVE-2026-72234, GHSA-mcgw-cw9v-8cmp, UBUNTU-CVE-2026-72234.