Cyber Resilience

CVE-2025-4981

Mattermost Server 9.11.0 – 9.11.16

Published
20 June 2025
Modified
17 June 2026
Patch / advisory
CVSS Score v3.1 9.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0073 51th percentile
Risk Priority 71 floored blend · peak EPSS

Summary

CVE-2025-4981 is a critical-severity Uncontrolled Search Path Element (CWE-427) vulnerability in Mattermost Mattermost Server. Its CVSS base score is 9.9 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Path Interception (T1034); ranked in the top 49% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to CM-6 (Configuration Settings) and AC-3 (Access Enforcement) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

Mattermost versions 10.5.x through 10.5.5, 9.11.x through 9.11.15, 10.8.x through 10.8.0, 10.7.x through 10.7.2, and 10.6.x through 10.6.5 contain a flaw in the archive extractor that does not sanitize filenames. The component fails to strip path traversal sequences when processing uploaded archives, and the issue is reachable on instances where FileSettings.EnableFileAttachments and FileSettings.ExtractContent remain at their default true values.

An authenticated user can upload an archive containing filenames with traversal sequences to write files to arbitrary locations on the server filesystem. Successful exploitation can result in remote code execution because the attacker controls both the destination path and file contents.

The Mattermost security updates advisory at https://mattermost.com/security-updates addresses remediation steps and patch availability for the listed affected releases.

The associated EPSS score has remained flat at 0.0169 with no material increase after disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Mattermost versions 10.5.x <= 10.5.5, 9.11.x <= 9.11.15, 10.8.x <= 10.8.0, 10.7.x <= 10.7.2, 10.6.x <= 10.6.5 fail to sanitize filenames in the archive extractor which allows authenticated users to write files to arbitrary locations on the filesystem via uploading…

more

archives with path traversal sequences in filenames, potentially leading to remote code execution. The vulnerability impacts instances where file uploads and document search by content is enabled (FileSettings.EnableFileAttachments = true and FileSettings.ExtractContent = true). These configuration settings are enabled by default.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1034 Path Interception Persistence
**This technique has been deprecated.
T1574.007 Path Interception by PATH Environment Variable Stealth
Adversaries may execute their own malicious payloads by hijacking environment variables used to load libraries.
T1574.008 Path Interception by Search Order Hijacking Stealth
Adversaries may execute their own malicious payloads by hijacking the search order used to load other programs.
T1574 Hijack Execution Flow Stealth
Adversaries may execute their own malicious payloads by hijacking the way operating systems run programs.
T1574.001 DLL Stealth
Adversaries may abuse dynamic-link library files (DLLs) in order to achieve persistence, escalate privileges, and evade defenses.
T1574.004 Dylib Hijacking Stealth
Adversaries may execute their own payloads by placing a malicious dynamic library (dylib) with an expected name in a path a victim application searches at runtime.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-3590Same product: Mattermost Mattermost Server
CVE-2026-20796Same product: Mattermost Mattermost Server
CVE-2023-6458Same product: Mattermost Mattermost Server
CVE-2023-4478Same product: Mattermost Mattermost Server
CVE-2024-2445Same product: Mattermost Mattermost Server
CVE-2024-4183Same product: Mattermost Mattermost Server
CVE-2026-2461Same product: Mattermost Mattermost Server
CVE-2025-9084Same product: Mattermost Mattermost Server
CVE-2023-1421Same product: Mattermost Mattermost Server
CVE-2023-3591Same product: Mattermost Mattermost Server

Affected Assets

mattermost
mattermost server
10.8.0 · 9.11.0 — 9.11.16 · 10.5.0 — 10.5.6 · 10.6.0 — 10.6.6

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 1 OS baseline
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

Establishes restrictive configuration settings that can define and lock down approved search paths.

Enforces approved authorizations so that only intended actors can place or modify elements in the search path.

Limits privileges so unintended actors cannot write to or control directories in the product's search path.

Restricts logical and physical access to change system configuration, including search-path settings and directories.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure-development practices directly address design of search paths and resource loading.

PR.PS-01 partial match
prevents

Hardened configuration baselines can enforce safe search-path settings and reduce exposure.

PR.PS-05 partial match
prevents

Execution allow-listing can block malicious binaries placed in hijackable search locations.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing can detect uncontrolled search-path issues but does not prevent them by itself.

mitigates

Restricting software installation reduces the chance that an attacker-controlled path element is introduced into the search path.

mitigates

Secure system architecture and engineering principles require explicit control over search paths and resource locations.

prevents

Secure coding practices directly address the use of fixed or controlled search paths that can be influenced by unintended actors.

prevents

Configuration management can enforce approved search-path settings but does not inherently prevent the weakness.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248577 OL 8 must enable kernel parameters to enforce Discretionary Access Control (DAC) on symlinks. prevents CWE-427

References