SecuriTricks - CVE-2026-6062

Description

Mattermost versions 11.7.x <= 11.7.0, 11.6.x <= 11.6.2, 11.5.x <= 11.5.5, 10.11.x <= 10.11.17 Fail to validate channel ownership of an existing subscription before applying edits which allows an authenticated attacker to hijack subscriptions from channels they have no access to via a crafted PUT request to the subscription edit endpoint.. Mattermost Advisory ID: MMSA-2026-00650

Product(s) Impacted

Vendor	Product	Versions
Mattermost	Mattermost	11.7.0, 11.6.2, 11.5.5, 10.11.17

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-639

Authorization Bypass Through User-Controlled Key

The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.

*CPE(s)

Affected systems and software identified for this CVE.

Type	Vendor	Product	Version	Update	Edition	Language	Software Edition	Target Software	Target Hardware	Other Information
a	mattermost	mattermost	11.7.0	/	/	/	/	/	/	/
a	mattermost	mattermost	11.6.2	/	/	/	/	/	/	/
a	mattermost	mattermost	11.5.5	/	/	/	/	/	/	/
a	mattermost	mattermost	10.11.17	/	/	/	/	/	/	/

References

https://mattermost.com/security-updates

CVSS Score

6.4 / 10

CVSS Data - 3.1

Attack Vector: NETWORK
Attack Complexity: HIGH
Privileges Required: LOW
Scope: UNCHANGED
Confidentiality Impact: HIGH
Integrity Impact: LOW
Availability Impact: LOW

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L

View Vector String

Timeline

Published: June 22, 2026, 2:17 p.m.
Last Modified: June 22, 2026, 6:29 p.m.

Status : Undergoing Analysis

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

[email protected]

CVE-2026-6062