# CVE-2026-64015: security/keys: fix missed RCU read section on lookup

> A race condition in the Linux kernel keyring allows attackers to trigger use-after-free errors, potentially leading to code execution or privilege escalation.

- **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:** 19 Jul 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-64015, DEBIAN-CVE-2026-64015, GHSA-6rrm-p5j2-8pf8, ROOT-OS-DEBIAN-11-CVE-2026-64015, ROOT-OS-UBUNTU-2204-CVE-2026-64015, UBUNTU-CVE-2026-64015

## What is CVE-2026-64015?

CVE-2026-64015 is a high-severity vulnerability in Linux kernel, published on 19 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:

security/keys: fix missed RCU read section on lookup

Nicholas Carlini reports that the keyring code calls assoc_array_find()
in find_key_to_update() without holding the RCU read lock, while the
assoc_array_gc() code really is designed around removing the node from
the tree and then freeing it after an RCU grace-period.

The regular key handling doesn't see this because holding the keyring
semaphore hides any lifetime issues, but the persistent key handling
uses a different model.

Instead of extending the keyring locking, just do the simple RCU locking
that the assoc_array was designed for.

Weakness: CWE-125 (Out-of-bounds Read), CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-64015?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-64015?

Apply the vendor's patch.

## Is CVE-2026-64015 being exploited?

There is no known exploitation of CVE-2026-64015 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-2026-64015 and fix it if it is affected.

What it is: CVE-2026-64015 is a high-severity vulnerability in Linux kernel, published on 19 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-2026-64015 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-2026-64015/ (Markdown: https://insights.sbomify.com/CVE-2026-64015/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64015
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64015
- OSV: https://osv.dev/vulnerability/CVE-2026-64015

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64015/
Summaries are generated and may contain mistakes; the official description above is the record.