# CVE-2026-11853: Path traversal in debusine

> Attackers can create arbitrary symbolic links via malicious Debian package manifests, potentially overwriting files and escalating privileges on build workers.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Jun 2026
- **Updated:** 10 Jun 2026
- **Also known as:** DEBIAN-CVE-2026-11853, GHSA-29fv-9q46-q5g2, UBUNTU-CVE-2026-11853

## What is CVE-2026-11853?

CVE-2026-11853 is a medium-severity path traversal vulnerability in Debian debusine, published on 10 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Debusine is an integrated solution to build, distribute and maintain a Debian-based distribution. Debian source packages (.dsc) and upload artifacts (.changes) are manifest files that name the files that make up the artifact. The parser used to read these files in Debusine accepted arbitrary fully user-controlled paths. The mergeuploads task could be abused to create arbitrary symbolic links on a worker, overwriting any file that the worker user has access to.

Weakness: CWE-59 (Improper Link Resolution Before File Access)

## Which versions are affected by CVE-2026-11853?


## How do I fix CVE-2026-11853?

Apply the vendor's patch.

## Is CVE-2026-11853 being exploited?

There is no known exploitation of CVE-2026-11853 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-11853 and fix it if it is affected.

What it is: CVE-2026-11853 is a medium-severity path traversal vulnerability in Debian debusine, published on 10 Jun 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-2026-11853 in the wild and no public exploit code.

Affected product: Debian debusine. 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-2026-11853/ (Markdown: https://insights.sbomify.com/CVE-2026-11853/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-11853
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-11853
- OSV: https://osv.dev/vulnerability/CVE-2026-11853

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-11853/
Summaries are generated and may contain mistakes; the official description above is the record.