---
title: "CVE-2025-4981: Mattermost allows authenticated users to write files to arbitrary locations"
url: https://erroneo.us/security/cve/CVE-2025-4981/
description: "CVE-2025-4981 (github.com/mattermost/mattermost-server (Go)): Mattermost versions 10.5.x"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-06-20
date_modified: 2025-06-20
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2025-4981"
kev: false
cvss: 9.9
epss: 0.0084
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2025-4981: Mattermost allows authenticated users to write files to arbitrary locations

**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 0.8% , percentile 57: FIRST’s model estimates a 0.8% chance of exploitation activity in the next 30 days, higher than 57% of all scored CVEs (moderate). 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 (Go) < 0.0.0-20250519205859-65aec10162f6, fixed in 0.0.0-20250519205859-65aec10162f6 ; github.com/mattermost/mattermost/server/v8 (Go) < 8.0.0-20250519205859-65aec10162f6, fixed in 8.0.0-20250519205859-65aec10162f6 ; github.com/mattermost/mattermost/server/v8 (Go) >= 10.5.0, <= 10.5.5, fixed in 10.5.6 ; github.com/mattermost/mattermost/server/v8 (Go) >= 9.11.0, <= 9.11.15, fixed in 9.11.16 . Check your lockfile, including transitive dependencies.

## What it is

Mattermost versions 10.5.x

## Affected packages

- Go `github.com/mattermost/mattermost-server` < 0.0.0-20250519205859-65aec10162f6 → fixed: 0.0.0-20250519205859-65aec10162f6
- Go `github.com/mattermost/mattermost/server/v8` < 8.0.0-20250519205859-65aec10162f6 → fixed: 8.0.0-20250519205859-65aec10162f6
- Go `github.com/mattermost/mattermost/server/v8` >= 10.5.0, <= 10.5.5 → fixed: 10.5.6
- Go `github.com/mattermost/mattermost/server/v8` >= 9.11.0, <= 9.11.15 → fixed: 9.11.16
- Go `github.com/mattermost/mattermost/server/v8` = 10.8.0 → fixed: 10.8.1
- Go `github.com/mattermost/mattermost/server/v8` >= 10.7.0, <= 10.7.2 → fixed: 10.7.3
- Go `github.com/mattermost/mattermost/server/v8` >= 10.6.0, <= 10.6.5 → fixed: 10.6.6

## Affected products (CVE record)

- Mattermost Mattermost: 10.5.0 <= 10.5.5, 9.11.0 <= 9.11.15, 10.8.0 <= 10.8.0, 10.7.0 <= 10.7.2, 10.6.0 <= 10.6.5

## 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): 0.84% probability of exploitation activity in the next 30 days; percentile 57.

## Sources

- [GitHub Advisory GHSA-qh58-9v3j-wcjc](https://github.com/advisories/GHSA-qh58-9v3j-wcjc)
- [CVE.org record CVE-2025-4981](https://www.cve.org/CVERecord?id=CVE-2025-4981)
- [NVD entry CVE-2025-4981](https://nvd.nist.gov/vuln/detail/CVE-2025-4981)
- [mattermost.com](https://mattermost.com/security-updates)
- [github.com](https://github.com/mattermost/mattermost/commit/65aec10162f612d98edf91cc66bf7e781868448b)

---
Source page: https://erroneo.us/security/cve/CVE-2025-4981/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt