CVE-2025-8285Network attack vector

Unauthorized channel subscriptions via missing access check

Published Aug 11, 2025 · Updated Aug 11, 2025

Missing authorization in Mattermost Confluence Plugin before 1.5.0 allows remote attackers to create subscriptions for inaccessible channels. The create-channel-subscription API accepts a target channel and persists the subscription without enforcing the caller's access to that channel. No Mattermost privileges are required, and successful exploitation writes an unauthorized notification subscription without disclosing channel content.

CVSS severity4.0
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authorization in Mattermost Confluence Plugin before 1.5.0 allows remote attackers to create subscriptions for inaccessible channels. The create-channel-subscription API accepts a target channel and persists the subscription without enforcing the caller's access to that channel. No Mattermost privileges are required, and successful exploitation writes an unauthorized notification subscription without disclosing channel content.

The record

CVE
CVE-2025-8285
Published
Aug 11, 2025
Updated
Aug 11, 2025
Vendor
Mattermost
Product
Mattermost Confluence Plugin
Classifications
CWE-862, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 11, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 11, 2025Record 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=0 <1.5.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mattermost · Mattermost Confluence Pluginversion=0 <1.5.0

Published CVSS scores

4.0MattermostCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N
5.3NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-862Missing Authorization
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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