6.5

CVE-2026-19541: mattermost

CVSS: 6.5v3.1MediumAwaiting analysis
Published 16-10-2026Last modified 16-10-2026
Open JSON

Vulnerability summary

CVE-2026-19541 is a medium (CVSS 6.5) vulnerability in mattermost. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 11.6% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.22%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 16-10-2026
    PublishedVulnerability first disclosed.
  2. 16-10-2026
    Last modifiedVulnerability information updated.

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 require re-entry of the stored client secret when validating an outgoing OAuth connection, which allows an authenticated user with permission to manage outgoing OAuth connections to obtain the secret via pointing the token URL at an attacker-controlled endpoint and triggering validation.. Mattermost Advisory ID: MMSA-2026-00761

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.22%

Chance of exploitation in the next 30 days

Percentile

12%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

16-10-202620-10-2026
EPSS score
0.22%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Mattermost1 product
  • mattermost≥ 11.9.0, ≤ 11.9.1 | ≥ 11.8.0, ≤ 11.8.5 | ≥ 11.7.0, ≤ 11.7.10 | ≥ 11.10.0, ≤ 11.10.1

1 vendor · 1 product

References

1 links