# CVE-2026-64370: posix-cpu-timers: Fix pid refcount leak in do_cpu_nanosleep() error path

> A refcount leak in the Linux kernel's posix-cpu-timers can lead to resource exhaustion and denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 15 Oct 2026
- **Also known as:** AZL-93861, BELL-CVE-2026-64370, DEBIAN-CVE-2026-64370, GHSA-cp5v-2q38-79vc, ROOT-OS-UBUNTU-2204-CVE-2026-64370, UBUNTU-CVE-2026-64370

## What is CVE-2026-64370?

CVE-2026-64370 is a medium-severity memory corruption 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:

posix-cpu-timers: Fix pid refcount leak in do_cpu_nanosleep() error path

In do_cpu_nanosleep(), posix_cpu_timer_create() takes a pid reference
via get_pid() and stores it in timer.it.cpu.pid. If the subsequent
posix_cpu_timer_set() call fails, the function returns immediately
without calling posix_cpu_timer_del() to release the pid reference,
causing a leak.

Fix it by calling posix_cpu_timer_del() before the unlock-and-return
on the error path, consistent with the other exit paths in the same
function.

## Which versions are affected by CVE-2026-64370?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-64370?

Apply the vendor's patch.

## Is CVE-2026-64370 being exploited?

There is no known exploitation of CVE-2026-64370 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-2026-64370 and fix it if it is affected.

What it is: CVE-2026-64370 is a medium-severity memory corruption 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-2026-64370 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-2026-64370/ (Markdown: https://insights.sbomify.com/CVE-2026-64370/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64370
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64370
- OSV: https://osv.dev/vulnerability/CVE-2026-64370

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64370/
Summaries are generated and may contain mistakes; the official description above is the record.