CVE-2026-6333 — SSRF via Host Header Spoofing in Custom Slash Commands
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 authenticate…
Published: 2026-05-18 · CVSS: 3.5 · CVSS 3.1
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
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7