# 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.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** Yes
- **Published:** 24 Jun 2026
- **Updated:** 19 Oct 2026
- **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, ROOT-OS-UBUNTU-2204-CVE-2026-52912, ROOT-OS-UBUNTU-2404-CVE-2026-52912, UBUNTU-CVE-2026-52912

## 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 (Use After Free)

## Which versions are affected by CVE-2026-52912?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-52912?

Apply the vendor's patch.

## 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

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-52912 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-52912 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-52912/ (Markdown: https://insights.sbomify.com/CVE-2026-52912/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-52912
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-52912
- OSV: https://osv.dev/vulnerability/CVE-2026-52912

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-52912/
Summaries are generated and may contain mistakes; the official description above is the record.