# CVE-2025-15570: ckolivas lrzip stream.c lzma_decompress_buf use after free

> A local attacker can exploit a use-after-free flaw in lrzip's lzma_decompress_buf function to potentially execute arbitrary code or cause a denial of service.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/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:** 6 May 2026
- **Also known as:** DEBIAN-CVE-2025-15570, GHSA-6gcc-w636-fgv2, UBUNTU-CVE-2025-15570

## What is CVE-2025-15570?

CVE-2025-15570 is a medium-severity use after free 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 vulnerability was found in ckolivas lrzip up to 0.651. This impacts the function lzma_decompress_buf of the file stream.c. Performing a manipulation results in use after free. Attacking locally is a requirement. The exploit has been made public and could be used. The project was informed of the problem early through an issue report but has not responded yet.

Weakness: CWE-416 (Use After Free), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2025-15570?

It affects 1 product.


Products: Ckolivas Lrzip.

## How do I fix CVE-2025-15570?

No fix published yet.

## Is CVE-2025-15570 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-15570 exists.

## Other vulnerabilities in ckolivas lrzip

- [CVE-2025-15571](https://insights.sbomify.com/CVE-2025-15571/): ckolivas lrzip stream.c ucompthread null pointer dereference (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-2025-15570 and fix it if it is affected.

What it is: CVE-2025-15570 is a medium-severity use after free 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-2025-15570 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-2025-15570/ (Markdown: https://insights.sbomify.com/CVE-2025-15570/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-15570
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-15570
- OSV: https://osv.dev/vulnerability/CVE-2025-15570

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From sbomify Insights: https://insights.sbomify.com/CVE-2025-15570/
Summaries are generated and may contain mistakes; the official description above is the record.