# CVE-2025-58084: Mattermost Desktop App crashes when clicking on malformed external URL

> An attacker can crash the Mattermost Desktop App by sending a malformed external URL, requiring users to upgrade to a patched version.

- **Severity:** Low 3.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 13 Oct 2025
- **Updated:** 14 Oct 2025
- **Also known as:** GHSA-c8m2-cx6j-jf7p

## What is CVE-2025-58084?

CVE-2025-58084 is a low-severity denial of service vulnerability in Mattermost, published on 13 Oct 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Mattermost Desktop App versions <= 5.13.0 fail to validate URLs external to the configured Mattermost servers, allowing an attacker on a server the user has configured to crash the user's application by sending the user a malformed URL.

Weakness: CWE-1287 (Improper Validation of Specified Type of Input)

## Which versions are affected by CVE-2025-58084?

It affects 1 product.


Products: Mattermost Mattermost Desktop.

## How do I fix CVE-2025-58084?

No fix has been published for CVE-2025-58084 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-58084 being exploited?

There is no known exploitation of CVE-2025-58084 in the wild and no public exploit code.

## Other vulnerabilities in Mattermost

- [CVE-2016-11064](https://insights.sbomify.com/CVE-2016-11064/): Code injection in n/a (critical 9.8)
- [CVE-2019-20856](https://insights.sbomify.com/CVE-2019-20856/): Code injection in n/a (critical 9.8)
- [CVE-2019-20861](https://insights.sbomify.com/CVE-2019-20861/): Code injection in n/a (high 8.8)
- [CVE-2026-1046](https://insights.sbomify.com/CVE-2026-1046/): Arbitrary application execution via unvalidated server-controlled URLs in Help menu (high 7.6)
- [CVE-2020-14456](https://insights.sbomify.com/CVE-2020-14456/): Security feature bypass in n/a (high 7.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-58084 and fix it if it is affected.

What it is: CVE-2025-58084 is a low-severity denial of service vulnerability in Mattermost, published on 13 Oct 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2025-58084 in the wild and no public exploit code.

Affected product: Mattermost. 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-2025-58084/ (Markdown: https://insights.sbomify.com/CVE-2025-58084/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-58084
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-58084
- OSV: https://osv.dev/vulnerability/CVE-2025-58084

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-58084/
Summaries are generated and may contain mistakes; the official description above is the record.