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ConfluenceApplication · Mattermost

CVE-2025-13523

MEDIUM · 5.4 CVSS v3.1 Published 2026-02-06
Fix available
A fix is available. Upgrade to 1.7.0 or later.
See remediation →
58/100
Remediation priority · Elevated
Remotely reachable

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Mattermost Confluence plugin version <1.7.0 fails to properly escape user-controlled display names in HTML template rendering which allows authenticated Confluence users with malicious display names to execute arbitrary JavaScript in victim browsers via sending a specially crafted OAuth2 connection link that, when visited, renders the attacker's display name without proper sanitization. Mattermost Advisory ID: MMSA-2025-00557

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The Mattermost Confluence plugin versions before 1.7.0 contain a stored XSS vulnerability where Confluence user display names are rendered in HTML templates without proper sanitization, allowing authenticated attackers to inject malicious JavaScript that executes in victim browsers when viewing the OAuth2 connection interface.

MitigationUpgrade the Mattermost Confluence plugin to version 1.7.0 or later which implements proper HTML escaping of user display names.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
ConfluenceApplication
Affected:>= 1.0.0, < 1.7.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Determine Mattermost Confluence plugin version
    In the Mattermost System Console, navigate to Plugin Management > Marketplace, or access the plugin configuration page. Locate the Confluence plugin and note the installed version number.
    Affected if The version is less than 1.7.0 (e.g., 1.0.0 through 1.6.x)
  2. Verify the plugin is enabled
    Check in Mattermost System Console > Plugin Management that the Confluence plugin status shows as Enabled.
    Affected if The plugin is currently enabled and the version is below 1.7.0
  3. Check if OAuth2 integration is configured
    Navigate to the Confluence plugin settings or the OAuth2 connection interface within Mattermost. Look for Confluence OAuth2 connection configuration.
    Affected if OAuth2 integration with Confluence has been configured or attempted, making the connection interface accessible to users
  4. Confirm user display names can be injected
    This requires examining whether Confluence users with malicious display names have authenticated to the connected Confluence instance. Check if any Confluence users who have connected their accounts have display names containing HTML or script tags.
    Affected if Confluence users with unsanitized display names exist in the connected Confluence instance and have authenticated via OAuth2

You are affected if the Mattermost Confluence plugin version is below 1.7.0, the plugin is enabled, and the OAuth2 connection interface is accessible, allowing Confluence user display names to be rendered without sanitization.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.7.0 or later
Fixed in 1.7.0
Interim mitigation

Upgrade the Mattermost Confluence plugin to version 1.7.0 or later which implements proper HTML escaping of user display names.

Recommended fix High confidence

1.7.0

  1. Obtain the Mattermost Confluence plugin version 1.7.0 or later from the official Mattermost marketplace or distribution channel
  2. Access the Mattermost System Console and navigate to the Plugins section
  3. Upload and install the updated Confluence plugin
  4. Restart the Mattermost server or reload plugins to ensure the new version is active
  5. Verify the plugin is running at version 1.7.0 or later in the Plugins management area

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Confluence Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,600
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-13523 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data