CVE-2026-6673

medium

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 authenticate Atlassian Connect installed callbacks, allowing a remote unauthenticated attacker to inject a rogue sharedSecret and disrupt the Jira integration via POST to /ac/installed during the pending-install window.. Mattermost Advisory ID: MMSA-2026-00654

References

https://mattermost.com/security-updates

Details

Source: Mitre, NVD

Published: 2026-06-22

Updated: 2026-06-22

Risk Information

CVSS v2

Base Score: 6.6

Vector: CVSS2#AV:N/AC:H/Au:S/C:N/I:C/A:C

Severity: Medium

CVSS v3

Base Score: 6.4

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