# CVE-2026-31532: can: raw: fix ro->uniq use-after-free in raw_rcv()

> A use-after-free in the Linux kernel CAN raw socket implementation allows attackers to potentially execute code or escalate privileges.

- **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:** 23 Apr 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-83538, BELL-CVE-2026-31532, DEBIAN-CVE-2026-31532, GHSA-7w6x-pfmg-76xx, ROOT-OS-DEBIAN-11-CVE-2026-31532, ROOT-OS-DEBIAN-12-CVE-2026-31532, ROOT-OS-DEBIAN-13-CVE-2026-31532, ROOT-OS-UBUNTU-2204-CVE-2026-31532, ROOT-OS-UBUNTU-2404-CVE-2026-31532, UBUNTU-CVE-2026-31532

## What is CVE-2026-31532?

CVE-2026-31532 is a high-severity use after free vulnerability in Linux kernel, published on 23 Apr 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:

can: raw: fix ro->uniq use-after-free in raw_rcv()

raw_release() unregisters raw CAN receive filters via can_rx_unregister(),
but receiver deletion is deferred with call_rcu(). This leaves a window
where raw_rcv() may still be running in an RCU read-side critical section
after raw_release() frees ro->uniq, leading to a use-after-free of the
percpu uniq storage.

Move free_percpu(ro->uniq) out of raw_release() and into a raw-specific
socket destructor. can_rx_unregister() takes an extra reference to the
socket and only drops it from the RCU callback, so freeing uniq from
sk_destruct ensures the percpu area is not released until the relevant
callbacks have drained.

[mkl: applied manually]

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-31532?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-31532?

Apply the vendor's patch.

## Is CVE-2026-31532 being exploited?

There is no known exploitation of CVE-2026-31532 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-2026-31532 and fix it if it is affected.

What it is: CVE-2026-31532 is a high-severity use after free vulnerability in Linux kernel, published on 23 Apr 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-2026-31532 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-2026-31532/ (Markdown: https://insights.sbomify.com/CVE-2026-31532/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31532
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31532
- OSV: https://osv.dev/vulnerability/CVE-2026-31532

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31532/
Summaries are generated and may contain mistakes; the official description above is the record.