CyberSecBulletin
CVE-2025-9079NVD status: Analyzed

Mattermost: Improper Limitation of a Pathname to a Restricted Directory

Published Updated By the CyberSecBulletin desk

CVE-2025-9079 is a high-severity improper limitation of a pathname to a restricted directory vulnerability in Mattermost, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected Mattermost versions: 10.8.0 through 10.8.3; 10.5.0 through 10.5.8; 9.11.0 through 9.11.17, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.64% chance of exploitation within 30 days, higher than 51% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Mattermost Server to 9.11.18 or 10.5.9 or 10.8.4 or 10.9.4, whichever matches your release line, or a later version.
  2. Read the advisory on mattermost.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
MattermostMattermost10.8.0 through 10.8.3; 10.5.0 through 10.5.8; 9.11.0 through 9.11.17; 10.10.0 through 10.10.1; 10.9.0 through 10.9.3Not stated
MattermostMattermost Server9.11.0 up to, but not including, 9.11.18; 10.5.0 up to, but not including, 10.5.9; 10.8.0 up to, but not including, 10.8.4; 10.9.0 up to, but not including, 10.9.4; 10.10.0 up to, but not including, 10.10.29.11.18, 10.5.9, 10.8.4, 10.9.4, 10.10.2

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
HighAdministrator-level access is required first.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.0HighCNA (mattermost.com)
CVSS 3.17.2HighNVD

Official description

Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 9.11.x <= 9.11.17, 10.10.x <= 10.10.1, 10.9.x <= 10.9.3 fail to validate import directory path configuration which allows admin users to execute arbitrary code via malicious plugin upload to prepackaged plugins directory

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Limitation of a Pathname to a Restricted Directory

The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

How developers prevent this class of flaw

  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
  • Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth.

More Improper Limitation of a Pathname to a Restricted Directory vulnerabilities (CWE-22)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Mattermost

All Mattermost vulnerabilities

Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities

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