CVE-2026-52912

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.

CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0014

Probability of exploitation

0.04%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/15d464265120ab9818bd673af301deee09bedab2 https://git.kernel.org/stable/c/19924bdd8a45ebc72a7b84c57fd63057d1dc75ac https://git.kernel.org/stable/c/1e5e20031c5eee8d2e490a90ff4d6a2feecfc3be https://git.kernel.org/stable/c/3823c27099cfe2482299065814adbaa771be9644 https://git.kernel.org/stable/c/3fb0f5c0f64162a8c3f25616a4f1e340b921737f https://git.kernel.org/stable/c/950d809f154dca04e5fbe5d3c8b9c5e44769cd57 https://git.kernel.org/stable/c/a698ac8ab2561cf575d2d9f34095032651dd952e https://git.kernel.org/stable/c/e196115ec330a18de415bdb9f5071aa9f08e53ce

Frequently Asked Questions

What is CVE-2026-52912? +

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. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2026-52912? +

CVE-2026-52912 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0014, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-52912? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.