# CVE-2026-74370: liveupdate: fix TOCTOU race in luo_session_retrieve()

> A time-of-check to time-of-use race condition in the Linux kernel liveupdate module allows local attackers to cause use-after-free, leading to privilege escalation or system crash.

- **Severity:** Not scored
- **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:** 15 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-74370, GHSA-rjgv-c7p2-jj9p, UBUNTU-CVE-2026-74370

## What is CVE-2026-74370?

CVE-2026-74370 is a vulnerability in Linux, published on 15 Aug 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:

liveupdate: fix TOCTOU race in luo_session_retrieve()

Extend the scope of the rwsem_read lock in luo_session_retrieve() to
overlap with the acquisition of the session mutex. This prevents a
concurrent thread from releasing and freeing the session between the
lookup and the mutex lock.

## Which versions are affected by CVE-2026-74370?


## How do I fix CVE-2026-74370?

Apply the vendor's patch.

## Is CVE-2026-74370 being exploited?

There is no known exploitation of CVE-2026-74370 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74370 and fix it if it is affected.

What it is: CVE-2026-74370 is a vulnerability in Linux, published on 15 Aug 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-2026-74370 in the wild and no public exploit code.

Affected product: Linux. 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-2026-74370/ (Markdown: https://insights.sbomify.com/CVE-2026-74370/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74370
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74370
- OSV: https://osv.dev/vulnerability/CVE-2026-74370

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74370/
Summaries are generated and may contain mistakes; the official description above is the record.