Dashboard / CVE-2026-19621

CVE-2026-19621

MEDIUM
MEDIUM Priority: 0.02 BB Relevance: 63/100
Published: 2026-10-16 Modified: 2026-10-27 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Interaction Conf. Impact

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: None
S: Unchanged
C: High
I: None
A: None

Description

Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to strip action integration secrets from post payloads before broadcasting post-deletion web socket events and returning thread API responses, which allows an authenticated channel member to obtain server-side webhook URLs and authentication context from interactive-message posts via the post_deleted websocket event or the threads REST API.. Mattermost Advisory ID: MMSA-2026-00766

Weakness Classification (1)

Affected Software (2)

VendorProductVersion
mattermost mattermost_server 11.7.0 – 11.7.10
mattermost mattermost_server 11.10.0

References & Advisories (1)

Bug Bounty Relevance

63 / 100
✓ Network accessible
✓ Low complexity
✓ No user interaction

CVSS Score

6.5 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS — Exploitation Probability

0.26%
Raw Score 0.002550
Percentile 17.1%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00255
2026-10-28
0.00255

Intelligence Sources

nvd ref →

External Links