CVE-2026-96259

medium

Description

Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to apply the internal-connection filter to OAuth endpoint requests, which allows a System Administrator to make the server issue requests to internal network addresses and read the responses via the configured OAuth token and userinfo endpoints.. Mattermost Advisory ID: MMSA-2026-00776

References

https://mattermost.com/security-updates

Details

Source: Mitre, NVD

Published: 2026-09-22

Updated: 2026-09-23

Risk Information

CVSS v2

Base Score: 4.7

Vector: CVSS2#AV:N/AC:L/Au:M/C:P/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 5.5

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