---
title: "CVE-2025-20051: Mattermost allows reading arbitrary files"
url: https://erroneo.us/security/cve/CVE-2025-20051/
description: "CVE-2025-20051 (github.com/mattermost/mattermost/server/v8 (Go)): Mattermost versions 10.4.x"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-02-24
date_modified: 2025-02-24
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2025-20051"
kev: false
cvss: 9.9
epss: 0.00611
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2025-20051: Mattermost allows reading arbitrary files

**Signal:** Critical, preconditions apply. Severe if exploited, but exploitation needs conditions that may not apply to you. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.6% , percentile 49: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 49% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes github.com/mattermost/mattermost/server/v8 (Go) < 8.0.0-20250122165010-4ed702ccff4e, fixed in 8.0.0-20250122165010-4ed702ccff4e ; github.com/mattermost/mattermost/server/v8 (Go) >= 9.11.0-rc1, < 9.11.8, fixed in 9.11.8 ; github.com/mattermost/mattermost/server/v8 (Go) >= 10.2.0-rc1, < 10.2.3, fixed in 10.2.3 ; github.com/mattermost/mattermost/server/v8 (Go) >= 10.3.0-rc1, < 10.3.3, fixed in 10.3.3 . Check your lockfile, including transitive dependencies.

## What it is

Mattermost versions 10.4.x

## Affected packages

- Go `github.com/mattermost/mattermost/server/v8` < 8.0.0-20250122165010-4ed702ccff4e → fixed: 8.0.0-20250122165010-4ed702ccff4e
- Go `github.com/mattermost/mattermost/server/v8` >= 9.11.0-rc1, < 9.11.8 → fixed: 9.11.8
- Go `github.com/mattermost/mattermost/server/v8` >= 10.2.0-rc1, < 10.2.3 → fixed: 10.2.3
- Go `github.com/mattermost/mattermost/server/v8` >= 10.3.0-rc1, < 10.3.3 → fixed: 10.3.3
- Go `github.com/mattermost/mattermost/server/v8` >= 10.4.0-rc1, < 10.4.2 → fixed: 10.4.2

## Affected products (CVE record)

- Mattermost Mattermost: 10.4.0 <= 10.4.1, 9.11.0 <= 9.11.7, 10.3.0 <= 10.3.2, 10.2.0 <= 10.2.2

## Severity

- Mattermost CVSS 3.1: 9.9 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.9 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.61% probability of exploitation activity in the next 30 days; percentile 49.

## Sources

- [GitHub Advisory GHSA-v469-7wp6-7cvp](https://github.com/advisories/GHSA-v469-7wp6-7cvp)
- [CVE.org record CVE-2025-20051](https://www.cve.org/CVERecord?id=CVE-2025-20051)
- [NVD entry CVE-2025-20051](https://nvd.nist.gov/vuln/detail/CVE-2025-20051)
- [mattermost.com](https://mattermost.com/security-updates)
- [github.com](https://github.com/mattermost/mattermost-plugin-boards/commit/025ce8d363a054473bc002f43f602a4032d38c06)
- [github.com](https://github.com/mattermost/mattermost/commit/4ed702ccff4ec3c9eff832a9b6060f9f4454141d)

---
Source page: https://erroneo.us/security/cve/CVE-2025-20051/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt