CVE-2025-9072

One-Click Mattermost Account Takeover via Poisoned RelayState SAML Parameter

State: Published
Severity: 7.6 High
Published: Sep 15, 2025
Updated: Sep 15, 2025
Reserved: Aug 15, 2025

Description

Mattermost versions 10.10.x <= 10.10.1, 10.5.x <= 10.5.9, 10.9.x <= 10.9.4 fail to validate the redirect_to parameter, allowing an attacker to craft a malicious link that, once a user authenticates with their SAML provider, could post the user’s cookies to an attacker-controlled URL.

Scores

CVSS	Score	Vector	Source
3.1	7.6 High	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:L	Mattermost

Weaknesses

CWE-601 CWE‑601: URL Redirection to Untrusted Site (“Open Redirect”)

Affected Products

Product	Versions
MattermostMattermost	10.10.0 through 10.10.1Affected 10.5.0 through 10.5.9Affected 10.9.0 through 10.9.4Affected 10.11.0Not affected 10.10.2Not affected 10.5.10Not affected 10.9.5Not affected

References

https://mattermost.com/security-updates

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