CVE-2026-18256

mediumpriority · track · 0OT risk · elevatedEPSS 0.002 · 5 %ileDE
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.16% (5th) EPSS
CVSS 4.3 · medium
Is it mine?
10 products
Check your exposure
Who says so?
1 sources
cert_bund

EPSS · scored 2026-10-27

Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to properly restrict private teams from public team search results, which allows an authenticated user without permission to list private teams to disclose the ID, name, and display name of private teams via a modified team search request. Mattermost Advisory ID: MMSA-2026-00748

01

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

v3.14.3mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:Nsecondary · responsibledisclosure@mattermost.comexploitability 2.8 · impact 1.4
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)
02

ssvc

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

Trackcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-863US
04

affected products (10)

Products and version ranges known to be affected.

05

advisories (1)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2026-4009Mattermost: Mehrere SchwachstellenDeutsch2026-10-15csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in Mattermost ausnutzen, um Sicherheitsvorkehrungen zu umgehen, um seine Privilegien zu erhöhen, um einen Denial of Service Angriff durchzuführen, um Informationen offenzulegen, um Dateien zu manipulieren.

06

sources

Which sources assert this record, and when.

cert_bundNVDCVE.orgMITRE
published 2026-10-16modified 2026-10-16
07

references (1) nvd

External citations — patches, advisories, analysis.

scry

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