CVE-2026-52912 netfilter: nf_queue: hold bridge skb->dev while queued
A use-after-free in the Linux kernel netfilter nf_queue allows attackers to execute code or escalate privileges via crafted bridge packets.
- 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-2026-52912?
CVE-2026-52912 is a high-severity use after free vulnerability in Linux kernel, published on 24 Jun 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:
netfilter: nf_queue: hold bridge skb->dev while queued
br_pass_frame_up() rewrites skb->dev from the ingress port to the bridge master before queueing bridge LOCAL_IN packets. NFQUEUE only holds references on state.in/out and bridge physdevs, so a queued bridge packet can retain a freed bridge master in skb->dev until reinjection.
When the verdict is reinjected later, br_netif_receive_skb() re-enters the receive path with skb->dev still pointing at the freed bridge master, triggering a use-after-free.
Store skb->dev in the queue entry, hold a reference on it for the queue lifetime, and use the saved device when dropping queued packets during NETDEV_DOWN handling.
Weakness: CWE-416
Which versions are affected by CVE-2026-52912?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-52912?
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-2026-52912 being exploited?
There is no known exploitation of CVE-2026-52912 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-90845, BELL-CVE-2026-52912, DEBIAN-CVE-2026-52912, GHSA-ffm7-9f73-pvmf, ROOT-OS-DEBIAN-11-CVE-2026-52912, ROOT-OS-DEBIAN-12-CVE-2026-52912 and 3 more.