CVE-2021-37867Network attack vector

Authenticated email disclosure via unprotected user API

Published Jan 18, 2022 · Updated Dec 6, 2024

Information exposure in Mattermost Boards 0.10.0 and earlier allows remote authenticated users to read every user's email address. A Boards API returns email fields for the full user list without enforcing authorization for those fields; Mattermost has not named the endpoint or code locus. Any signed-in user can obtain the addresses, while the published impact is limited to disclosure with no reported data modification or service interruption.

CVSS severity4.3
Medium
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information exposure in Mattermost Boards 0.10.0 and earlier allows remote authenticated users to read every user's email address. A Boards API returns email fields for the full user list without enforcing authorization for those fields; Mattermost has not named the endpoint or code locus. Any signed-in user can obtain the addresses, while the published impact is limited to disclosure with no reported data modification or service interruption.

The record

CVE
CVE-2021-37867
Published
Jan 18, 2022
Updated
Dec 6, 2024
Vendor
Mattermost
Product
Mattermost Boards
Classifications
CWE-200, T1087
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 18, 2022CVE publishedPublication date reported by the CVE source.
  2. Dec 6, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <=0.10.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mattermost · Mattermost Boardsversion=unspecified <=0.10.0

Published CVSS scores

4.3MattermostCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1087Account Discovery

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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