Riskcovery

CVE-2026-6333

SSRF via Host Header Spoofing in Custom Slash Commands

State
Published
Severity
3.5 Low
Published
May 18, 2026
Updated
May 19, 2026
Reserved
Apr 15, 2026

Read the record on cve.org

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

Scores

CVSSScoreVectorSource
3.13.5 LowCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:NMattermost

Weaknesses

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

Affected Products

ProductVersions
MattermostMattermost
  • 11.5.0 through 11.5.1Affected
  • 10.11.0 through 10.11.13Affected
  • 11.6.0Not affected
  • 11.5.2Not affected
  • 10.11.14Not affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.