Mattermost Go Module up to 0.1.21 public path traversal

CVSS Meta Temp Score
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CTI Interest Score
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5.7$0-$5k0.00

Summaryinfo

A vulnerability was found in Mattermost Go Module up to 0.1.21 and classified as critical. Affected by this vulnerability is an unknown functionality of the file /mattermost/mattermost/server/public. The manipulation results in path traversal. This vulnerability is cataloged as CVE-2026-13426. The attack may be launched remotely. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Mattermost Go Module up to 0.1.21. It has been classified as critical. Affected is an unknown code of the file /mattermost/mattermost/server/public. The manipulation with an unknown input leads to a path traversal vulnerability. CWE is classifying the issue as CWE-22. 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. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

The Mattermost Go module github.com/mattermost/mattermost/server/public versions < v0.1.22 fail to validate path parameters when constructing API route paths which allows an attacker to redirect API calls to unintended endpoints via crafted IDs containing path traversal components. Mattermost Advisory ID: MMSA-2025-00532

The weakness was shared by Juho Forsén. The advisory is available at mattermost.com. This vulnerability is traded as CVE-2026-13426 since 06/26/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1006 by the MITRE ATT&CK project.

Upgrading to version 0.1.22 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-2107). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

  • Mattermost Mattermost

Productinfo

Type

Vendor

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.9
VulDB Meta Temp Score: 5.7

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.4
CNA Vector (Mattermost): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Path traversal
CWE: CWE-22
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Go Module 0.1.22

Timelineinfo

06/26/2026 Advisory disclosed
06/26/2026 +0 days CVE reserved
06/26/2026 +0 days VulDB entry created
07/14/2026 +18 days VulDB entry last update

Sourcesinfo

Advisory: mattermost.com
Researcher: Juho Forsén
Status: Confirmed

CVE: CVE-2026-13426 (🔒)
GCVE (CVE): GCVE-0-2026-13426
GCVE (VulDB): GCVE-100-374154
CERT Bund: WID-SEC-2026-2107 - Mattermost Server: Mehrere Schwachstellen

Entryinfo

Created: 06/26/2026 17:07
Updated: 07/14/2026 08:11
Changes: 06/26/2026 17:07 (66), 07/14/2026 08:11 (7)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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