# CVE-2026-93106: crash_dump: release keyring reference at the correct time

> A use-after-free vulnerability in the Linux kernel's crash_dump module allows local attackers with high privileges to cause a system crash or potentially escalate privileges.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-93106, DEBIAN-CVE-2026-93106, GHSA-ggxj-6q52-m3ww, UBUNTU-CVE-2026-93106

## What is CVE-2026-93106?

CVE-2026-93106 is an use after free vulnerability in Linux, published on 17 Sep 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:

crash_dump: release keyring reference at the correct time

restore_dm_crypt_keys_to_thread_keyring() gets a reference to the user
keyring before restoring the saved dm-crypt keys.

The same keyring reference is then passed to add_key_to_keyring() for each
saved key, but add_key_to_keyring() drops that reference on every call.
This is only balanced when exactly one key is restored. With multiple
keys, the keyring reference is dropped too many times and may trigger a
refcount underflow or use-after-free.

When more than five keys are restored, a refcount underflow/use-after-free
warning can be triggered.

The early error paths after lookup_user_key() also return without dropping
the keyring reference.

Keep ownership of the keyring reference in
restore_dm_crypt_keys_to_thread_keyring(), drop it once on all exit paths,
and make add_key_to_keyring() only use the reference without consuming it.

## Which versions are affected by CVE-2026-93106?


## How do I fix CVE-2026-93106?

Apply the vendor's patch.

## Is CVE-2026-93106 being exploited?

There is no known exploitation of CVE-2026-93106 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93106 and fix it if it is affected.

What it is: CVE-2026-93106 is an use after free vulnerability in Linux, published on 17 Sep 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-2026-93106 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-2026-93106/ (Markdown: https://insights.sbomify.com/CVE-2026-93106/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93106
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93106
- OSV: https://osv.dev/vulnerability/CVE-2026-93106

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93106/
Summaries are generated and may contain mistakes; the official description above is the record.