CVE-2026-4273CWE-863broken-access-control

CVE-2026-4273

Low · published May 18, 2026

CVSS v3.1
3.7
EPSS
0%
Percentile
3.2
In the wild
Unconfirmed
What it is

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation which allows an authenticated attacker to bypass token rotation and reuse the original invite token via sending a crafted invite confirmation with a RefreshedToken matching the original token. Mattermost Advisory ID: MMSA-2026-00575

The record
Technical detail
CVSS v3.1
3.7 · LOW
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00142 · 3.2th percentile
Weakness
CWE-863 · Incorrect Authorization
Published
2026-05-18T12:16Z
Affected products (2)
ProductVersionsFixed in
mattermost/mattermost_server≥ 10.11.0, < 10.11.1410.11.14
mattermost/mattermost_server≥ 11.5.0, < 11.5.211.5.2
References (1)
https://mattermost.com/security-updates · [email protected]
EPSS history
Timeline
  • 18 MAY 06:56Z
    Insufficient token rotation validation in remote cluster invite confirmation
    cvelistv5