MEDIUMCVSS v3.1 5.0Vulnerability

CVE-2026-18223

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

Properties

Severity
MEDIUM
Nvd fetched at
2026-10-20T21:14:08.448323+00:00
Epss score
0.00161
Cvss score
5
Cvss severity
MEDIUM
Retrieved at
2026-10-21T01:24:49+00:00
Last source
FIRST EPSS
Score
5
Cvss version
3.1
Cve id
CVE-2026-18223
Cvss vector
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:L/A:N
First seen by Signal
2026-10-18T13:39:03+00:00
Vector
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:L/A:N
Published at
2026-10-16T08:17:12.753
Last modified
2026-10-16T19:23:18.623
Epss percentile
0.04843

Related Entities (1)

HAS_WEAKNESS (1)

Explore deeper with Ninja Signal's threat intelligence graph

CVE-2026-18223 (CVSS v3.1 5) — Ninja Signal Threat Intelligence | Ninja Signal