CVE-2023-3613Network attack vector

Guest channel access via missing membership validation

Published Jul 17, 2023 · Updated Oct 21, 2024

Incorrect authorization in Mattermost WelcomeBot plugin before 1.3.0 allows remote authenticated users to gain unintended channel access. When inviting or adding users to configured channels, the plugin fails to validate guest membership status and includes guest accounts by default. A guest account and interaction with a configured welcome action are required, and the resulting access exposes only channel information available to members.

CVSS severity3.5
Low
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in Mattermost WelcomeBot plugin before 1.3.0 allows remote authenticated users to gain unintended channel access. When inviting or adding users to configured channels, the plugin fails to validate guest membership status and includes guest accounts by default. A guest account and interaction with a configured welcome action are required, and the resulting access exposes only channel information available to members.

The record

CVE
CVE-2023-3613
Published
Jul 17, 2023
Updated
Oct 21, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-863, T1098
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 17, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 21, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

3.5Mattermost, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N
3.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1098Account Manipulation

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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