# CVE-2026-53247: net: ethernet: mtk_eth_soc: Fix use-after-free in metadata dst teardown

> A use-after-free in the MediaTek Ethernet driver allows attackers to cause denial of service or execute arbitrary code via improper memory handling.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Jun 2026
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2026-53247, DEBIAN-CVE-2026-53247, GHSA-mm4j-fwqr-3cf4, ROOT-OS-UBUNTU-2404-CVE-2026-53247, UBUNTU-CVE-2026-53247

## What is CVE-2026-53247?

CVE-2026-53247 is a critical use after free vulnerability in Linux kernel, published on 25 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

net: ethernet: mtk_eth_soc: Fix use-after-free in metadata dst teardown

mtk_free_dev() calls metadata_dst_free() which frees the metadata_dst
with kfree() immediately, bypassing the RCU grace period.
In the RX path, skb_dst_set_noref() sets a non-refcounted pointer from
the skb to the metadata_dst. This function requires RCU read-side
protection and the dst must remain valid until all RCU readers complete.
Since metadata_dst_free() calls kfree() directly, a use-after-free can
occur if any skb still holds a noref pointer to the dst when the driver
tears it down.
Replace metadata_dst_free() with dst_release() which properly goes
through the refcount path: when the refcount drops to zero, it schedules
the actual free via call_rcu_hurry(), ensuring all RCU readers have
completed before the memory is freed.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-53247?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-53247?

Apply the vendor's patch.

## Is CVE-2026-53247 being exploited?

There is no known exploitation of CVE-2026-53247 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-2026-53247 and fix it if it is affected.

What it is: CVE-2026-53247 is a critical use after free vulnerability in Linux kernel, published on 25 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-53247 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-2026-53247/ (Markdown: https://insights.sbomify.com/CVE-2026-53247/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53247
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53247
- OSV: https://osv.dev/vulnerability/CVE-2026-53247

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53247/
Summaries are generated and may contain mistakes; the official description above is the record.