# CVE-2026-53157: net: phonet: free phonet_device after RCU grace period

> A use-after-free vulnerability in the Linux kernel's Phonet subsystem allows attackers to potentially execute code or escalate privileges via improper memory handling.

- **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:** 25 Jun 2026
- **Updated:** 4 Jul 2026
- **Also known as:** AZL-90455, BELL-CVE-2026-53157, DEBIAN-CVE-2026-53157, GHSA-w8w6-f4mm-hw75, ROOT-OS-DEBIAN-11-CVE-2026-53157, ROOT-OS-DEBIAN-12-CVE-2026-53157, ROOT-OS-DEBIAN-13-CVE-2026-53157, ROOT-OS-UBUNTU-2204-CVE-2026-53157, ROOT-OS-UBUNTU-2404-CVE-2026-53157, UBUNTU-CVE-2026-53157

## What is CVE-2026-53157?

CVE-2026-53157 is a high-severity use after free vulnerability in Linux kernel, published on 25 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:

net: phonet: free phonet_device after RCU grace period

phonet_device_destroy() removes a phonet_device from the per-net device
list with list_del_rcu(), but frees it immediately. RCU readers walking
the same list can still hold a pointer to the object after it has been
removed, leading to a slab-use-after-free.

Use kfree_rcu(), matching the lifetime rule already used by
phonet_address_del() for the same object type.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-53157?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-53157?

Apply the vendor's patch.

## Is CVE-2026-53157 being exploited?

There is no known exploitation of CVE-2026-53157 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-2026-53157 and fix it if it is affected.

What it is: CVE-2026-53157 is a high-severity use after free vulnerability in Linux kernel, published on 25 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-2026-53157 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-2026-53157/ (Markdown: https://insights.sbomify.com/CVE-2026-53157/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53157
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53157
- OSV: https://osv.dev/vulnerability/CVE-2026-53157

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53157/
Summaries are generated and may contain mistakes; the official description above is the record.