SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2023-27266

Mattermost fails to honor the ShowEmailAddress setting when constructing a response to the /api/v4/users/me/teams API endpoint, allowing an attacker with team admin privileges to learn the team owner's email address in the response.

LOW 2.7EPSS 0.53%

Does this matter?

Lower severity and a low EPSS score (0.53%). Track it; it rarely justifies an emergency change on its own.

Description

Mattermost fails to honor the ShowEmailAddress setting when constructing a response to the /api/v4/users/me/teams API endpoint, allowing an attacker with team admin privileges to learn the team owner's email address in the response.

CVSS 3.1
2.7 LOWCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N
EPSS
0.53% probability · 43th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-200
Affected
mattermost/mattermost server
Source
responsibledisclosure@mattermost.com
EPSS trend
0%3%5%10 October 2026: 0.53%10 October 202610 October 2026

EPSS 0.5% since 10 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.