5.4

CVE-2026-13426: mattermost github.com/mattermost/mattermost/server/public Path Traversal

CVSS: 5.4v3.1MediumAwaiting analysis
Published 26-06-2026Last modified 26-06-2026
Open JSON

Vulnerability summary

CVE-2026-13426 is a medium (CVSS 5.4) Path Traversal vulnerability in mattermost github.com/mattermost/mattermost/server/public. EPSS estimates a 0.29% chance of exploitation in the next 30 days, higher than 20.3% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.4/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.29%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 26-06-2026
    PublishedVulnerability first disclosed.
  2. 26-06-2026
    Last modifiedVulnerability information updated.

Description

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

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.29%

Chance of exploitation in the next 30 days

Percentile

20%

Versus all other CVEs

30-day change

0.00 pp

From 0.29% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.29%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Mattermost1 product

1 vendor · 1 product

References

1 links