CVE-2026-46233 batman-adv: bla: only purge non-released claims
A race condition in the batman-adv module can cause a null pointer dereference, leading to a kernel crash and 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-2026-46233?
CVE-2026-46233 is a medium-severity vulnerability in Linux kernel, published on 28 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:
batman-adv: bla: only purge non-released claims
When batadv_bla_purge_claims() goes through the list of claims, it is only traversing the hash list with an rcu_read_lock(). Due to a potential parallel batadv_claim_put(), it can happen that it encounters a claim which was actually in the process of being released+freed by batadv_claim_release(). In this case, backbone_gw is set to NULL before the delayed RCU kfree is started. Calling batadv_bla_claim_get_backbone_gw() is then no longer allowed because it would cause a NULL-ptr derefence.
To avoid this, only claims with a valid reference counter must be purged. All others are already taken care of.
Weakness: CWE-476
Which versions are affected by CVE-2026-46233?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-46233?
Apply the vendor's patch.
Is CVE-2026-46233 being exploited?
There is no known exploitation of CVE-2026-46233 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-88893, BELL-CVE-2026-46233, DEBIAN-CVE-2026-46233, GHSA-vvwr-mg55-mhmm, ROOT-OS-DEBIAN-11-CVE-2026-46233, ROOT-OS-DEBIAN-12-CVE-2026-46233 and 3 more.