4.3

CVE-2025-11777: mattermost Incorrect Authorization

CVSS: 4.3v3.1MediumAnalyzed
AliasesGHSA-mqcj-8c2g-h97qGO-2025-4122
Published 13-11-2025Last modified 13-11-2025
Open JSON

Vulnerability summary

CVE-2025-11777 is a medium (CVSS 4.3) Incorrect Authorization vulnerability in mattermost. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 8.7% of scored vulnerabilities.

Overall risk
17/100
0100
Low · default modelHow is this calculated?
CVSS score
4.3/10
010
Medium · v3.1 (NVD)
EPSS score
0.20%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2 · Related 2
OPENSUSE-SU-2026:21483-1SUSE-SU-2026:0037-1

Timeline

  1. 13-11-2025
    PublishedVulnerability first disclosed.
  2. 13-11-2025
    Last modifiedVulnerability information updated.

Description

Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.20%

Chance of exploitation in the next 30 days

Percentile

9%

Versus all other CVEs

30-day change

+0.01 pp

From 0.18% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.20%

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

Github.com/mattermost2 products
  • mattermost< 5.3.2-0.20250905150616-ba86dfc5876b | All versions (No fix recorded)
  • mattermost-server≥ 10.11.0, < 10.11.4 | ≥ 10.5.0, < 10.5.12 | < 5.3.2-0.20250905150616-ba86dfc5876b | ≥ 10.11.0+incompatible, < 10.11.4+incompatible
Github.com/mattermost/mattermost-server2 products
  • v5< 5.3.2-0.20250905150616-ba86dfc5876b | All versions (No fix recorded)
  • v6< 5.3.2-0.20250905150616-ba86dfc5876b | All versions (No fix recorded)
Mattermost2 products
Github.com/mattermost/mattermost1 product
  • v5All versions (No fix recorded)
Github.com/mattermost/mattermost/server1 product
  • v8< 8.0.0-20250905150616-ba86dfc5876b | < 8.0.0-20251212204551-54f2e9b4afd5

5 vendors · 8 products

References

7 links