dbcve.org
DiscourseApplication

CVE-2023-45131

HIGH · 7.5 CVSS v3.1 Published 2023-10-16
Fix available
A fix is available. Upgrade to after 3.1.1 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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
Discourse is an open source platform for community discussion. New chat messages can be read by making an unauthenticated POST request to MessageBus. This issue is patched in the 3.1.1 stable and 3.2.0.beta2 versions of Discourse. Users are advised to upgrade. There are no known workarounds for this vulnerability.

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

An information disclosure vulnerability in Discourse allows unauthenticated attackers to read new chat messages by making a POST request to the MessageBus endpoint, enabling unauthorized access to private communications.

MitigationUpgrade to Discourse 3.1.1 stable or 3.2.0.beta2 or later. No workarounds exist; immediate patching is required.

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
DiscourseApplication
Affected:<= 3.1.1= 3.2.0

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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. Identify installed Discourse version
    Check your Discourse instance version by accessing /about or checking the admin dashboard. Compare against affected versions: <= 3.1.1 or = 3.2.0
    Affected if Installed version is 3.1.1 or earlier, or exactly 3.2.0
  2. Verify Chat plugin is enabled
    Navigate to Discourse admin panel > Plugins > Chat settings, or inspect the discourse_chat plugin configuration in your database. Confirm whether the Chat feature is turned on.
    Affected if Chat plugin is enabled and the Discourse version is in the affected range
  3. Confirm MessageBus is active
    Check if the MessageBus service is running on your Discourse server. This is typically accessible at /messagebus or verify the service process is active.
    Affected if MessageBus endpoint is accessible and the Discourse version is in the affected range
  4. Check for unauthenticated MessageBus access
    Test if a POST request to the MessageBus endpoint (typically /messagebus) can be made without authentication using curl or similar tool: curl -X POST https://your-site.com/messagebus -I
    Affected if The endpoint responds without requiring authentication, indicating the vulnerability is present

Your environment is affected if Discourse is at version 3.1.1 or earlier, or exactly 3.2.0, and the Chat feature with MessageBus is enabled, allowing unauthenticated access to chat messages.

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 a release after 3.1.1
Interim mitigation

Upgrade to Discourse 3.1.1 stable or 3.2.0.beta2 or later. No workarounds exist; immediate patching is required.

Recommended fix High confidence

Discourse 3.1.1 stable (for 3.1.x) or Discourse 3.2.0.beta2 or later (for 3.2.x); prefer latest stable release in your version branch

  1. Identify your current Discourse version by checking the admin panel or running `git log` in your Discourse installation directory
  2. For Discourse 3.1.x line: Upgrade to version 3.1.1 or later stable release
  3. For Discourse 3.2.x line: Upgrade to version 3.2.0.beta2 or later (preferably the latest stable 3.2.x release)
  4. After upgrade, verify the patch is applied by confirming chat messages cannot be read via unauthenticated POST requests to MessageBus
  5. Review admin logs to ensure no unauthorized MessageBus access occurred prior to patching
Caveat Standard Discourse upgrade considerations apply - review release notes for theme/plugin compatibility and database migration requirements

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

Fix this in Discourse Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing3.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-45131 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2023-45131 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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