CVE-2025-11777

mediumpriority · track · 17OT risk · elevatedEPSS 0.002 · 9 %ileDEEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.20% (9th) EPSS

CVSS 4.3 · medium

Is it mine?

28 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · osv · cert_bund

EPSS · scored 2026-10-27

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

Technical severity, 0–10. One row per scoring source.

4.3

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 3.1–4.3

v3.14.3mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:Nprimary · NVD / NIST USexploitability 2.8 · impact 1.4

v3.13.1lowCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:Nsecondary · ENISA EU

v3.13.1lowCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:Nsecondary · responsibledisclosure@mattermost.comexploitability 1.6 · impact 1.4

v3.13.1lowCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:Nsecondary · OSV

v3.14mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-863USCWE-863US

affected products (28)

Products and version ranges known to be affected.

Mattermost Mattermost Mobile <2.33.0all versionscert_bundDE
Mattermost Mattermost Server <10.11.4all versionscert_bundDE
Mattermost Mattermost Server <10.12.1all versionscert_bundDE
Mattermost Mattermost Server <10.5.12all versionscert_bundDE
Mattermost Mattermost Server <11.0.0all versionscert_bundDE
Mattermost Mattermost≤ Server <10.12.1cert_bundDE
Mattermost Mattermost≤ Mobile <2.33.0cert_bundDE
Mattermost Mattermost≤ Server <10.11.4cert_bundDE
Mattermost Mattermost≤ Server <10.5.12cert_bundDE
Mattermost Mattermost≤ Server <11.0.0cert_bundDE
Mattermost Mattermost≤ 10.5.0 ≤10.5.11enisa_euvdEU
Mattermost Mattermost≤ 10.11.0 ≤10.11.3enisa_euvdEU
mattermost mattermost server10.11.0 → 10.11.4nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost server10.5.0 → 10.5.12nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
Go github.com/mattermost/mattermostall versionsosvUSpkg:golang/github.com/mattermost/mattermost
Go github.com/mattermost/mattermost< 5.3.2-0.20250905150616-ba86dfc5876bosvUSpkg:golang/github.com/mattermost/mattermost
Go github.com/mattermost/mattermost-server< 5.3.2-0.20250905150616-ba86dfc5876bosvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server10.11.0 → 10.11.4osvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server10.11.0+incompatible → 10.11.4+incompatibleosvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server10.5.0 → 10.5.12osvUSpkg:golang/github.com/mattermost/mattermost-server

showing 20 of 28

advisories (3)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2025-2315Mattermost Server und Mobile: Mehrere SchwachstellenDeutsch2025-10-15csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Mattermost Server und Mobile ausnutzen, um Informationen offenzulegen oder einen Denial of Service zu verursachen.
GHSA-mqcj-8c2g-h97qMattermost Incorrect Authorization vulnerability2025-11-13ghsa · osvUS
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.
GO-2025-4122Mattermost Incorrect Authorization vulnerability in github.com/mattermost/mattermost2025-11-17vendor · osvUS
Mattermost Incorrect Authorization vulnerability in github.com/mattermost/mattermost

also known as (5)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd osv cert_bund nvd NVD CVE.org MITRE

published 2025-11-13modified 2026-10-19

references (5)

External citations — patches, advisories, analysis.

scry

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