CVE-2026-18223

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

EPSS · scored 2026-10-28

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 validate the invited recipient's email address when redeeming team and guest invitation tokens, which allows an authenticated attacker to join a team or gain unauthorized access to private channels via a forwarded or leaked invitation link.. Mattermost Advisory ID: MMSA-2026-00747

01

cvss

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

5.0
010

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

v3.15mediumCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:L/A:Nsecondary · responsibledisclosure@mattermost.comexploitability 0.7 · impact 4.2
v3.14.6mediumCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:L/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

Products and version ranges known to be affected.

No affected products recorded.

05

sources

Which sources assert this record, and when.

NVDCVE.orgMITRE
published 2026-10-16modified 2026-10-16
06

references (1) nvd

External citations — patches, advisories, analysis.

scry

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