SecuriTricks - CVE-2026-6046

Description

Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 fail to validate that a username returned during bot registration belongs to a bot account, which allows an unprivileged attacker to intercept private messages sent by plugins via direct message channels by pre-registering a user account with a predictable plugin bot username.. Mattermost Advisory ID: MMSA-2026-00649

Product(s) Impacted

Vendor	Product	Versions
Mattermost	Mattermost	11.6.0-11.6.1, 11.5.0-11.5.4, 10.11.0-10.11.15, 10.11.0-10.11.16

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-200

Exposure of Sensitive Information to an Unauthorized Actor

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

*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	11.6.0-11.6.1	/	/	/	/	/	/	/
a	mattermost	mattermost	11.5.0-11.5.4	/	/	/	/	/	/	/
a	mattermost	mattermost	10.11.0-10.11.15	/	/	/	/	/	/	/
a	mattermost	mattermost	10.11.0-10.11.16	/	/	/	/	/	/	/

References

https://mattermost.com/security-updates

CVSS Score

5.3 / 10

CVSS Data - 3.1

Attack Vector: NETWORK
Attack Complexity: HIGH
Privileges Required: LOW
Scope: UNCHANGED
Confidentiality Impact: HIGH
Integrity Impact: NONE
Availability Impact: NONE

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

View Vector String

Timeline

Published: June 12, 2026, 5:16 p.m.
Last Modified: June 12, 2026, 5:16 p.m.

Status : Received

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

More info

Source

[email protected]

CVE-2026-6046