CVE-2025-53514Network attack vector

Unauthenticated plugin crash via nil event dereference

Published Aug 11, 2025 · Updated Aug 11, 2025

Improper exceptional-condition handling in Mattermost Confluence Plugin before 1.5.0 allows remote attackers to crash the plugin. The server webhook deserializes malformed event bodies with absent page, comment, or space objects, then notification code dereferences those nil objects and panics. No authentication is required, but sustained invalid requests are needed to repeatedly interrupt plugin service.

CVSS severity5.9
Medium
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper exceptional-condition handling in Mattermost Confluence Plugin before 1.5.0 allows remote attackers to crash the plugin. The server webhook deserializes malformed event bodies with absent page, comment, or space objects, then notification code dereferences those nil objects and panics. No authentication is required, but sustained invalid requests are needed to repeatedly interrupt plugin service.

The record

CVE
CVE-2025-53514
Published
Aug 11, 2025
Updated
Aug 11, 2025
Vendor
Mattermost
Product
Mattermost Confluence Plugin
Classifications
CWE-754, T1499
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

Compare your product and version with the public record. A matching version still requires validation against your environment.

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

5.9MattermostCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-754Improper Check for Unusual or Exceptional Conditions
T1499Endpoint Denial of Service

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo