# CVE-2026-10600: Denial of service via unbounded document content extraction in Mattermost Server

> Authenticated users can cause denial of service by uploading small documents that exhaust server resources during content extraction.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/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:** Not needed
- **Fix available:** Yes
- **Published:** 27 Jul 2026
- **Updated:** 27 Jul 2026
- **Also known as:** GHSA-hmmp-647g-6q22, MINI-4m7p-rw8c-h6xp, MINI-mmmg-666r-h548

## What is CVE-2026-10600?

CVE-2026-10600 is a medium-severity denial of service vulnerability in Mattermost Mattermost Server, published on 27 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Mattermost versions 11.8.x <= 11.8.0, 11.7.x <= 11.7.3, 11.6.x <= 11.6.5, 10.11.x <= 10.11.20 fail to bound the time and resource consumption of server-side document content extraction which allows an authenticated user with file-upload permission to degrade file uploads for all users on the server via repeatedly uploading small documents that are cheap to upload but expensive to extract, saturating the shared extraction worker pool.. Mattermost Advisory ID: MMSA-2026-00694

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-10600?

It affects 1 product.


Products: Mattermost Mattermost Server.

## How do I fix CVE-2026-10600?

Upgrade to a fixed version.

## Is CVE-2026-10600 being exploited?

There is no known exploitation of CVE-2026-10600 in the wild and no public exploit code.

## Other vulnerabilities in Mattermost Mattermost Server

- [CVE-2025-12419](https://insights.sbomify.com/CVE-2025-12419/): Account takeover on OAuth/OpenID-enabled servers (critical 9.9)
- [CVE-2025-12421](https://insights.sbomify.com/CVE-2025-12421/): Account Takeover via Code Exchange Endpoint (critical 9.9)
- [CVE-2025-4981](https://insights.sbomify.com/CVE-2025-4981/): Path Traversal Leading to RCE by Any Authenticated Mattermost User (critical 9.9)
- [CVE-2025-20051](https://insights.sbomify.com/CVE-2025-20051/): Arbitrary file read via block duplication in Mattermost Boards (critical 9.9)
- [CVE-2025-25279](https://insights.sbomify.com/CVE-2025-25279/): Arbitrary file read in Mattermost Boards via import & export board archive (critical 9.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-10600 and fix it if it is affected.

What it is: CVE-2026-10600 is a medium-severity denial of service vulnerability in Mattermost Mattermost Server, published on 27 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-10600 in the wild and no public exploit code.

Affected product: Mattermost Mattermost Server. 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-2026-10600/ (Markdown: https://insights.sbomify.com/CVE-2026-10600/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-10600
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-10600
- OSV: https://osv.dev/vulnerability/CVE-2026-10600

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-10600/
Summaries are generated and may contain mistakes; the official description above is the record.