# CVE-2025-15571: ckolivas lrzip stream.c ucompthread null pointer dereference

> A local attacker can cause a denial of service via null pointer dereference in lrzip's ucompthread function.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P`)
- **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:** 10 Feb 2026
- **Updated:** 23 Feb 2026
- **Also known as:** DEBIAN-CVE-2025-15571, GHSA-x954-5gxx-h6v4, UBUNTU-CVE-2025-15571

## What is CVE-2025-15571?

CVE-2025-15571 is a medium-severity vulnerability in ckolivas lrzip, published on 10 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A security vulnerability has been detected in ckolivas lrzip up to 0.651. This vulnerability affects the function ucompthread of the file stream.c. Such manipulation leads to null pointer dereference. The attack can only be performed from a local environment. The exploit has been disclosed publicly and may be used. The project was informed of the problem early through an issue report but has not responded yet.

Weakness: CWE-476 (NULL Pointer Dereference), CWE-404 (Improper Resource Shutdown or Release)

## Which versions are affected by CVE-2025-15571?

It affects 1 product.


Products: Ckolivas Lrzip.

## How do I fix CVE-2025-15571?

No fix published yet.

## Is CVE-2025-15571 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-15571 exists.

## Other vulnerabilities in ckolivas lrzip

- [CVE-2025-15570](https://insights.sbomify.com/CVE-2025-15570/): ckolivas lrzip stream.c lzma_decompress_buf use after free (medium 4.8)
- [CVE-2025-9396](https://insights.sbomify.com/CVE-2025-9396/): ckolivas lrzip strtol_l.c __GI_____strtol_l_internal null pointer dereference (medium 4.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-15571 and fix it if it is affected.

What it is: CVE-2025-15571 is a medium-severity vulnerability in ckolivas lrzip, published on 10 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-15571 exists.

Affected product: ckolivas lrzip. 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-2025-15571/ (Markdown: https://insights.sbomify.com/CVE-2025-15571/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-15571
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-15571
- OSV: https://osv.dev/vulnerability/CVE-2025-15571

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-15571/
Summaries are generated and may contain mistakes; the official description above is the record.