CVE-2026-6333

3.5 LOW

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 sla...

Published: 2026-05-18 · Last updated: 2026-05-19

Severity and scoring

CVSS: 3.5 LOW
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N
CWE: CWE-918

Affected products

Vendor	Product
mattermost	mattermost_server

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

Source: NVD

References

[NVD]https://nvd.nist.gov/vuln/detail/CVE-2026-6333
[Vendor advisory]https://mattermost.com/security-updates

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