# CVE-2025-27791: Collabora Online Vulnerable to Arbitrary File Write

> A path traversal flaw in Collabora Online allows arbitrary file writes via malicious WOPI server responses, potentially leading to code execution.

- **Severity:** High 8.3 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Apr 2025
- **Updated:** 15 Apr 2025
- **Also known as:** GHSA-9j32-gg3j-8w25

## What is CVE-2025-27791?

CVE-2025-27791 is a high-severity path traversal vulnerability in CollaboraOnline online, published on 15 Apr 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Collabora Online is a collaborative online office suite based on LibreOffice technology. In versions prior to 24.04.12.4, 23.05.19, and 22.05.25, there is a path traversal flaw in handling the CheckFileInfo BaseFileName field returned from WOPI servers. This allows for a file to be written anywhere the uid running Collabora Online can write, if such a response was supplied by a malicious WOPI server. By combining this flaw with a Time of Check, Time of Use DNS lookup issue with a WOPI server address under attacker control, it is possible to present such a response to be processed by a Collabora Online instance. This issue has been patched in versions 24.04.13.1, 23.05.19, and 22.05.25.

Weakness: CWE-23 (Relative Path Traversal)

## Which versions are affected by CVE-2025-27791?


## How do I fix CVE-2025-27791?

No fix has been published for CVE-2025-27791 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-27791 being exploited?

There is no known exploitation of CVE-2025-27791 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-27791 and fix it if it is affected.

What it is: CVE-2025-27791 is a high-severity path traversal vulnerability in CollaboraOnline online, published on 15 Apr 2025. 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-2025-27791 in the wild and no public exploit code.

Affected product: CollaboraOnline online. 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-2025-27791/ (Markdown: https://insights.sbomify.com/CVE-2025-27791/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-27791
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-27791
- OSV: https://osv.dev/vulnerability/CVE-2025-27791

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-27791/
Summaries are generated and may contain mistakes; the official description above is the record.