CVE-2024-56328
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 · uneditedDiscourse is an open source platform for community discussion. An attacker can execute arbitrary JavaScript on users' browsers by posting a maliciously crafted onebox url. This issue only affects sites with CSP disabled. This problem has been patched in the latest version of Discourse. Users are advised to upgrade. Users unable to upgrade should enable CSP, disable inline Oneboxes globally, or allow specific domains for Oneboxing.
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 confidenceDiscourse is vulnerable to stored XSS via maliciously crafted onebox URLs that allow arbitrary JavaScript execution in user browsers. The vulnerability only affects Discourse instances with Content Security Policy (CSP) disabled, making it a conditional but exploitable vector for authenticated attackers posting content.
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< 3.3.3< 3.4.0= 3.4.0CVSS 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
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/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 checksWork through these to decide whether this CVE applies to you.
-
Identify installed Discourse versionAccess the Discourse admin panel and navigate to /about or use the Discourse console command to retrieve the current version numberAffected if Version is below 3.3.3, or between 3.3.3 and 3.4.0 exclusive, or exactly 3.4.0
-
Verify Content Security Policy statusCheck the Discourse site settings for Content-Security-Policy headers. In the admin panel, navigate to Security settings or inspect HTTP headers on any page response for 'Content-Security-Policy'Affected if CSP is disabled or not configured, meaning no CSP headers are served
-
Confirm Onebox feature is enabledCheck Discourse site settings for Onebox-related configuration. Look for settings like 'enable_onebox' or allowlisting of domains for Oneboxing in the admin settingsAffected if Oneboxing is enabled and accessible to authenticated users posting content
-
Verify user content submission is possibleConfirm that authenticated users can post content containing URLs. Check if the site allows new posts, topics, or messages from logged-in usersAffected if Authenticated users can submit posts containing external URLs that get Oneboxed
A user is affected if their Discourse version falls within the vulnerable range AND CSP is disabled AND the Onebox feature is available to authenticated users posting content.
Generated from the published advisory. Verify against your own configuration.
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 · scoped3.3.33.4.0
Enable Content Security Policy (CSP) to block inline script execution, disable inline Oneboxes globally, or restrict Oneboxing to specific trusted domains. Alternatively, upgrade to the latest patched Discourse version.
Latest stable Discourse release (version > 3.4.0)
- 1. Backup your Discourse installation and database before upgrading
- 2. Update Discourse to the latest stable release using your current installation method (e.g., ./discourse-upgrade for Docker installations)
- 3. After upgrading, verify the version number matches the patched release
- 4. Confirm the onebox functionality works correctly with the patch applied
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,424.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2024-56328 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2024-56328 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
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.
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.
- 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