CVE-2026-4055

mediumpriority · track · 0OT risk · elevatedEPSS 0.002 · 4 %ileDEEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.15% (4th) EPSS

CVSS 4.3 · medium

Is it mine?

21 products

Check your exposure

Who says so?

6 sources

cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-27

Mattermost versions 11.5.x <= 11.5.1 fail to validate team-level run_create permission against the target team when creating a playbook run which allows an authenticated team member to create runs in teams where they lack permission via specifying a different team ID in the run creation API request. Mattermost Advisory ID: MMSA-2026-00629

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

v3.14.3mediumAV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:Nsecondary · FSTEC (BDU) RU

v3.14.3mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:Nsecondary · ENISA EU

v3.14.3mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:Nsecondary · responsibledisclosure@mattermost.comexploitability 2.8 · impact 1.4

v3.14.3mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:Nsecondary · OSV

v3.14mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/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-863USCWE-863US

affected products (21)

Products and version ranges known to be affected.

Mattermost Mattermost <10.11.15all versionscert_bundDE
Mattermost Mattermost <11.4.5all versionscert_bundDE
Mattermost Mattermost <11.5.4all versionscert_bundDE
Mattermost Mattermost <11.6.1all versionscert_bundDE
Mattermost Mattermost <11.7.0all versionscert_bundDE
Mattermost Mattermost< 10.11.15cert_bundDE
Mattermost Mattermost< 11.4.5cert_bundDE
Mattermost Mattermost< 11.5.4cert_bundDE
Mattermost Mattermost< 11.6.1cert_bundDE
Mattermost Mattermost< 11.7.0cert_bundDE
Mattermost Mattermost≤ 11.5.0 ≤11.5.1enisa_euvdEU
Mattermost Inc Mattermost10.11.0 → 10.11.17fstec_bduRU
Mattermost Inc Mattermost11.5.0 → 11.5.5fstec_bduRU
Mattermost Inc Mattermost11.6.0 → 11.6.2fstec_bduRU
mattermost mattermost server10.11.0 → 10.11.17nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost server11.5.0 → 11.5.5nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost server11.6.0 → 11.6.2nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
Go github.com/mattermost/mattermost-serverall versionsosvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server/v5all versionsosvUSpkg:golang/github.com/mattermost/mattermost-server/v5
Go github.com/mattermost/mattermost-server/v6all versionsosvUSpkg:golang/github.com/mattermost/mattermost-server/v6

showing 20 of 21

advisories (3)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2026-1173Mattermost: Mehrere Schwachstellen ermöglichen nicht spezifizierten AngriffDeutsch2026-04-19csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Mattermost ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.
GHSA-6cfr-wp44-6qmvMattermost has an Incorrect Authorization issue2026-05-21ghsa · osvUS
Mattermost versions 11.5.x <= 11.5.1 fail to validate team-level run_create permission against the target team when creating a playbook run which allows an authenticated team member to create runs in teams where they lack permission via specifying a different team ID in the run creation API request. Mattermost Advisory ID: MMSA-2026-00629.
GO-2026-5173Mattermost has an Incorrect Authorization issue in github.com/mattermost/mattermost-server2026-06-25vendor · osvUS
Mattermost has an Incorrect Authorization issue in github.com/mattermost/mattermost-server

also known as (7)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu osv cert_bund nvd NVD CVE.org MITRE

published 2026-05-21modified 2026-07-23

references (4)

External citations — patches, advisories, analysis.

scry

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