DiscourseApplication

CVE-2023-48297

HIGH · 7.5 CVSS v3.1 Published 2024-01-12
Fix available
A fix is available. Upgrade to 3.1.4 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 a platform for community discussion. The message serializer uses the full list of expanded chat mentions (@all and @here) which can lead to a very long array of users. This issue was patched in versions 3.1.4 and beta 3.2.0.beta5.

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 Discourse message serializer expands chat mentions (@all and @here) to include the full list of all users in the channel, creating a very large array. This can cause performance degradation and potential resource exhaustion when serializing messages in communities with many users.

MitigationUpgrade Discourse to version 3.1.4 or beta 3.2.0.beta5 or later, which contains the patch for this vulnerability.

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:< 3.1.4= 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
None
Integrity
None
Availability
High

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

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. Check installed Discourse version
    Access the Rails console or admin panel and run: Discourse::VERSION::STRING or check /admin/about in the web interface
    Affected if The version displayed is less than 3.1.4 or equals 3.2.0 exactly
  2. Confirm Chat feature is enabled
    Navigate to Admin > Site Settings and search for 'chat' or check if the chat plugin is active in the plugins list
    Affected if Chat functionality is enabled and users can post in chat channels
  3. Verify chat mention serialization behavior
    Inspect the message serializer code in the Discourse source, specifically looking for chat mention expansion logic that expands @all and @here to user arrays
    Affected if The serializer expands mentions to full user arrays rather than using references or limits
  4. Monitor for large serialized message payloads
    Check serialized chat message sizes in the database or application logs when messages containing @all or @here are posted
    Affected if Messages containing @all or @here produce unusually large serialized payloads compared to other mentions

A user is affected if their Discourse version is < 3.1.4 or = 3.2.0 AND the chat feature is enabled with messages using @all or @here mentions being processed by the serializer.

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 3.1.4 or later
Fixed in 3.1.4
Interim mitigation

Upgrade Discourse to version 3.1.4 or beta 3.2.0.beta5 or later, which contains the patch for this vulnerability.

Recommended fix High confidence

Discourse 3.1.4 (stable) or 3.2.0.beta5 (beta) or later

  1. Back up your Discourse instance and database before upgrading
  2. Upgrade Discourse to version 3.1.4 or later for stable releases
  3. If using beta, upgrade to version 3.2.0.beta5 or later
  4. Verify the upgrade completed successfully
  5. Test chat functionality to confirm the mention serialization issue is resolved
Caveat Standard Discourse upgrade precautions apply - review release notes for any configuration or plugin compatibility changes

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
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,272.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-48297 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2023-48297 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