# CVE-2026-64311: crypto: loongson - Remove broken and unused loongson-rng

> A use-after-free vulnerability in the Linux kernel's loongson-rng driver allows attackers to potentially execute code or cause a denial of service.

- **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 Jul 2026
- **Updated:** 17 Aug 2026
- **Also known as:** BELL-CVE-2026-64311, DEBIAN-CVE-2026-64311, GHSA-x266-xjm8-j78q, ROOT-OS-UBUNTU-2204-CVE-2026-64311, UBUNTU-CVE-2026-64311

## What is CVE-2026-64311?

CVE-2026-64311 is a high-severity use after free vulnerability in Linux kernel, published on 25 Jul 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:

crypto: loongson - Remove broken and unused loongson-rng

The loongson-rng rng_alg has several vulnerabilities, including not
providing forward security, and a use-after-free bug due to the use of
wait_for_completion_interruptible().

Meanwhile, the rng_alg framework doesn't really have any purpose in the
first place other than to access the software algorithms crypto/drbg.c
and crypto/jitterentropy.c.  Hardware-specific rng_algs have no
in-kernel user, and unlike hwrng there's no feed into the actual Linux
RNG.  As such, there's really no point to this code.  There are of
course other rng_alg drivers that are similarly unused, but they're
similarly in the process of being phased out, e.g.
https://lore.kernel.org/r/20260529193648.18172-1-ebiggers@kernel.org and
https://lore.kernel.org/r/20260529220430.34135-1-ebiggers@kernel.org

Given that, there's no point in fixing forward these vulnerabilities,
and it makes much more sense to simply roll back the addition of this
driver.  If this platform provides TRNG (not PRNG) functionality, it
could make sense to add a hwrng driver, but it would be quite different.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-64311?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-64311?

Apply the vendor's patch.

## Is CVE-2026-64311 being exploited?

There is no known exploitation of CVE-2026-64311 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-2026-64311 and fix it if it is affected.

What it is: CVE-2026-64311 is a high-severity use after free vulnerability in Linux kernel, published on 25 Jul 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-2026-64311 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-2026-64311/ (Markdown: https://insights.sbomify.com/CVE-2026-64311/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64311
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64311
- OSV: https://osv.dev/vulnerability/CVE-2026-64311

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64311/
Summaries are generated and may contain mistakes; the official description above is the record.