CVE-2026-9571

mediumpriority · track · 26EPSS 0.003 · 23 %ileDEEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.30% (23rd) EPSS

CVSS 6.5 · medium

Is it mine?

14 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · cert_bund · nvd

EPSS · scored 2026-10-28

Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to invalidate OAuth refresh tokens upon user account deactivation, which allows a deactivated user or an attacker in possession of a valid refresh token to obtain new functional access tokens via the OAuth refresh token grant endpoint.. Mattermost Advisory ID: MMSA-2026-00680

cvss

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

6.5

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:Nprimary · NVD / NIST USexploitability 2.8 · impact 3.6

v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:Nsecondary · ENISA EU

v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:Nsecondary · responsibledisclosure@mattermost.comexploitability 0.7 · impact 5.2

v3.16mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:Usecondary · CVSS-BT (t0sche)

ssvc

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

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-305US

affected products (14)

Products and version ranges known to be affected.

Mattermost Mattermost Server <10.11.20all versionscert_bundDE
Mattermost Mattermost Server <11.6.5all versionscert_bundDE
Mattermost Mattermost Server <11.7.3all versionscert_bundDE
Mattermost Mattermost Server <11.8.0all versionscert_bundDE
Mattermost Mattermost≤ Server <11.8.0cert_bundDE
Mattermost Mattermost≤ Server <10.11.20cert_bundDE
Mattermost Mattermost≤ Server <11.6.5cert_bundDE
Mattermost Mattermost≤ Server <11.7.3cert_bundDE
Mattermost Mattermost≤ 10.11.0 ≤10.11.19enisa_euvdEU
Mattermost Mattermost≤ 11.7.0 ≤11.7.2enisa_euvdEU
Mattermost Mattermost≤ 11.6.0 ≤11.6.4enisa_euvdEU
mattermost mattermost server10.11.0 → 10.11.20nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost server11.6.0 → 11.6.5nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost server11.7.0 → 11.7.3nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*

advisories (1)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2026-1932Mattermost: Mehrere Schwachstellen ermöglichen nicht spezifizierten AngriffDeutsch2026-06-15csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Mattermost ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd cert_bund nvd NVD CVE.org MITRE

published 2026-07-13modified 2026-07-15

references (3)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan