Security Digest · Vulnerability record

CVE-2025-20051: Mattermost allows reading arbitrary files

Mattermost versions 10.4.x

CVSS 9.9 Critical EPSS 0.6% · p49

Should you act?

Critical, preconditions apply

Severe if exploited, but exploitation needs conditions that may not apply to you. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

  • 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

From the GitHub advisory

Mattermost versions 10.4.x

Weakness type: CWE-22.

Product: github.com/mattermost/mattermost/server/v8 (Go) · Assigned by: Mattermost · Published: 2025-02-24

Affected and fixed versions

EcosystemPackageVulnerableFirst fixed
Gogithub.com/mattermost/mattermost/server/v8< 8.0.0-20250122165010-4ed702ccff4e8.0.0-20250122165010-4ed702ccff4e
Gogithub.com/mattermost/mattermost/server/v8>= 9.11.0-rc1, < 9.11.89.11.8
Gogithub.com/mattermost/mattermost/server/v8>= 10.2.0-rc1, < 10.2.310.2.3
Gogithub.com/mattermost/mattermost/server/v8>= 10.3.0-rc1, < 10.3.310.3.3
Gogithub.com/mattermost/mattermost/server/v8>= 10.4.0-rc1, < 10.4.210.4.2
VendorProductAffected versions (per CVE record)
MattermostMattermost10.4.0 <= 10.4.1, 9.11.0 <= 9.11.7, 10.3.0 <= 10.3.2, 10.2.0 <= 10.2.2

Severity scores

Scored byCVSSScoreVector
Mattermost3.19.9 CriticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
GitHub3.19.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
  • Attack vector: network (remotely reachable)
  • Attack complexity: low
  • Privileges required: low (any account)
  • User interaction: none
  • Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

  • 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.

Timeline

  • — CVE record last updated
  • — CVE record published by Mattermost
  • — GitHub-reviewed advisory GHSA-v469-7wp6-7cvp published (critical)

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

  1. GitHub Advisory GHSA-v469-7wp6-7cvp github.com
  2. CVE.org record CVE-2025-20051 cve.org
  3. NVD entry CVE-2025-20051 nvd.nist.gov

Other references from the CVE record and advisory

  1. mattermost.com mattermost.com
  2. github.com github.com
  3. github.com github.com

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