# CVE-2026-56004: obs-service-tar_scm: command injection via mercurial handler

> Attackers can execute arbitrary code by providing a malicious _service file to the mercurial handler in the Open Build Service tar_scm source service.

- **Severity:** Critical 10.0 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 2 Jul 2026
- **Updated:** 2 Jul 2026
- **Also known as:** GHSA-f3xh-pcqp-fpcm, openSUSE-SU-2026:11189-1

## What is CVE-2026-56004?

CVE-2026-56004 is a critical command injection vulnerability in openSUSE buildservice, published on 2 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A shellcode injection in the mercurial handler of the obs tar_scm source service before version 0.12.4 could be used by attackers able to provide a _service file to execute code as the source service or the local user checking out the malicious services

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2026-56004?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `obs-service-tar_scm` | openSUSE:Tumbleweed | All versions | 0.12.4-1.1 |

## How do I fix CVE-2026-56004?

Upgrade to a fixed version.

## Is CVE-2026-56004 being exploited?

There is no known exploitation of CVE-2026-56004 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-56004 and fix it if it is affected.

What it is: CVE-2026-56004 is a critical command injection vulnerability in openSUSE buildservice, published on 2 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-56004 in the wild and no public exploit code.

Affected product: openSUSE buildservice. 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-2026-56004/ (Markdown: https://insights.sbomify.com/CVE-2026-56004/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-56004
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-56004
- OSV: https://osv.dev/vulnerability/CVE-2026-56004

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-56004/
Summaries are generated and may contain mistakes; the official description above is the record.