Is CVE-2025-20086 in the CISA KEV catalog?

No. CVE-2025-20086 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2025-20086?

CVE-2025-20086 has a CVSS v3 base score of 6.5 (MEDIUM).

What is the EPSS score for CVE-2025-20086?

CVE-2025-20086 has an EPSS score of 0.41% (33th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2025-20086?

Upgrade mattermost server to 10.1.4 or later.

CVE & CISA-KEV Catalog

CVE-2025-20086

MEDIUM

6.5

CVSS v3

NVD

Description

Mattermost versions 10.2.x <= 10.2.0, 9.11.x <= 9.11.5, 10.0.x <= 10.0.3, 10.1.x <= 10.1.3 fail to properly validate post props which allows a malicious authenticated user to cause a crash via a malicious post.

CWE-1287Improper Validation of Specified Type of Input

How to fix

Remediation Available

mattermost serverNVD

Affected:>= 10.1.0, < 10.1.4Fixed in:10.1.4CVE-2025-20086derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Exploit Intelligence

0.41%probability of exploitation in 30 days

33rdpercentile

Low risk: more likely to be exploited than 33% of all known CVEs.

References

Vendor Advisory1

mattermost.com

Embed a live status badge for CVE-2025-20086

Markdown

[![CVE-2025-20086](https://tridentstack.com/cve/badge/CVE-2025-20086.svg)](https://tridentstack.com/cve/CVE-2025-20086)

HTML

<a href="https://tridentstack.com/cve/CVE-2025-20086"><img src="https://tridentstack.com/cve/badge/CVE-2025-20086.svg" alt="CVE-2025-20086"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-09-30.