Use After Free Affecting kernel-rt-debug-devel package, versions <0:4.18.0-553.168.1.rt7.509.el8_10


Severity

Recommended
high

Based on AlmaLinux security rating.

Threat Intelligence

EPSS
0.2% (9th percentile)

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  • Snyk IDSNYK-ALMALINUX8-KERNELRTDEBUGDEVEL-20137451
  • published25 Sept 2026
  • disclosed24 Sept 2026

Introduced: 24 Sep 2026

NewCVE-2026-52912  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade AlmaLinux:8 kernel-rt-debug-devel to version 0:4.18.0-553.168.1.rt7.509.el8_10 or higher.
This issue was patched in ALSA-2026:71330.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-rt-debug-devel package and not the kernel-rt-debug-devel package as distributed by AlmaLinux. See How to fix? for AlmaLinux:8 relevant fixed versions and status.

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 Base Scores

version 3.1