CVE-2026-6333

MEDIUM EPSS 3.5%
Published May 18, 20261mo ago · Modified Jun 17, 20262w ago
5.0 CVSS 3.1
Medium
Find Similar
Published May 18, 2026 1mo ago
Last Modified Jun 17, 2026 2w ago

Description

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to validate the Host header when constructing response URLs for custom slash commands which allows an authenticated attacker to redirect slash command responses to an attacker-controlled server via a spoofed Host header.. Mattermost Advisory ID: MMSA-2026-00582

CVSS Details

Base Score
5.0
Exploitability
3.1
Impact
1.4
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Changed
Confidentiality None
Integrity Low
Availability None

Threat Intelligence

EPSS Exploit Probability
3.5% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-918 Server-Side Request Forgery (SSRF) Validation

Affected Products 2

VendorProductVersionRange
mattermostmattermost_server*≥10.11.0  –  <10.11.14
mattermostmattermost_server*≥11.5.0  –  <11.5.2

References 1

  • mattermost.com https://mattermost.com/security-updates
    Vendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.