Cyber Resilience

CVE-2025-25279

Critical

Published: 24 February 2025

Published
24 February 2025
Modified
02 October 2025
KEV Added
Patch
CVSS Score v3.1 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.5909 98.3th percentile
Risk Priority 55 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-25279 is a critical-severity Path Traversal (CWE-22) vulnerability in Mattermost Mattermost Server. Its CVSS base score is 9.9 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 1.7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 RA-5 (Vulnerability Monitoring and Scanning) and SI-10 (Information Input Validation).

Deeper analysis

Mattermost versions 10.4.x up to 10.4.1, 9.11.x up to 9.11.7, 10.3.x up to 10.3.2, and 10.2.x up to 10.2.2 contain a path traversal flaw in the Boards feature. The software fails to validate board blocks during import operations, enabling an attacker to supply a crafted archive that reads arbitrary files from the underlying system when the archive is later exported.

An authenticated user with access to import boards can exploit the weakness over the network without user interaction. Successful exploitation grants the ability to read any file on the server filesystem and may extend to full confidentiality, integrity, and availability impacts given the CVSS 9.9 rating and scope change.

The official Mattermost security advisory at https://mattermost.com/security-updates addresses the issue and directs administrators to apply the corresponding updates that restore proper validation of board blocks during import and export operations.

The associated EPSS score has reached a peak of 0.6120 with a current value of 0.5909, indicating sustained exploitation interest following disclosure.

EU & UK References

Vulnerability details

Mattermost versions 10.4.x <= 10.4.1, 9.11.x <= 9.11.7, 10.3.x <= 10.3.2, 10.2.x <= 10.2.2 fail to properly validate board blocks when importing boards which allows an attacker could read any arbitrary file on the system via importing and exporting a…

more

specially crafted import archive in Boards.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
Why these techniques?

Path traversal in Mattermost Boards import allows exploitation of the network-accessible application (T1190) to read arbitrary local system files (T1005).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2025-20051Same product: Mattermost Mattermost Server
CVE-2026-4858Same product: Mattermost Mattermost Server
CVE-2025-14273Same product: Mattermost Mattermost Server
CVE-2025-25068Same product: Mattermost Mattermost Server
CVE-2025-20621Same product: Mattermost Mattermost Server
CVE-2025-25274Same product: Mattermost Mattermost Server
CVE-2025-24490Same product: Mattermost Mattermost Server
CVE-2026-6346Same product: Mattermost Mattermost Server
CVE-2025-1412Same product: Mattermost Mattermost Server
CVE-2026-3108Same product: Mattermost Mattermost Server

Affected Assets

mattermost
mattermost server
9.11.0 — 9.11.8 · 10.2.0 — 10.2.3 · 10.3.0 — 10.3.3

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires validation of board import archive blocks to block path traversal payloads that enable arbitrary server file reads.

prevent

Mandates timely identification, reporting, and correction of the specific board import validation flaw across affected Mattermost versions.

prevent

Requires vulnerability scanning of Mattermost installations to detect and remediate this path traversal vulnerability before exploitation.

References