CVE-2023-29196
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. This vulnerability is not exploitable on the default install of Discourse. A custom feature must be enabled for it to work at all, and the attacker’s payload must pass the CSP to be executed. However, if an attacker succeeds in embedding Javascript that does pass the CSP, it could result in session hijacking for any users that view the attacker’s post. The vulnerability is patched in the latest tests-passed, beta and stable branches. Users are advised to upgrade. Users unable to upgrade should enable and/or restore your site's CSP to the default one provided with Discourse. Remove any embed-able hosts configured.
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 contains a stored cross-site scripting (XSS) vulnerability that allows attackers to embed malicious JavaScript in posts. The vulnerability is only exploitable when a custom feature is enabled and the attacker's payload successfully bypasses the Content Security Policy (CSP). Successful exploitation can lead to session hijacking for any user viewing the affected post.
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< 3.0.3< 3.1.0= 3.1.0CVSS 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.
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Check the installed Discourse versionAccess the Discourse admin panel and navigate to /about or use the Discourse API to retrieve the version number. Alternatively, check the version file in the Discourse installation directory if you have server access.Affected if The version is less than 3.0.3, or is 3.1.0, or is any version below 3.1.1 (e.g., 3.0.0, 3.0.2, 3.1.0, 3.0.1).
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Verify if the embedding feature is enabledIn the Discourse admin panel, navigate to the Embedding settings (usually under Settings > Embedding). Check if 'allow embed' or a similar option is enabled, and verify if any hosts are configured in 'embeddable hosts'.Affected if Embedding is enabled and one or more hosts are listed in the embeddable hosts configuration.
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Inspect the Content Security Policy configurationIn the Discourse admin panel, navigate to the Security settings and review the Content Security Policy (CSP) headers. Check if the default CSP has been modified or if exceptions have been added for embedded content.Affected if The default CSP has been modified, relaxed, or contains exceptions that allow scripts from external embeddable hosts.
You are affected if your Discourse version is below 3.1.1 AND the embedding feature with custom embeddable hosts is enabled AND your CSP has been customized to allow the attacker's payload to execute.
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 · scoped3.0.33.1.0
Upgrade Discourse to the latest tests-passed, beta, or stable branch. If unable to upgrade, restore the default CSP and remove any configured embed-able hosts.
Latest stable/beta/tests-passed branch (version > 3.1.0)
- 1. Back up your Discourse installation and database before proceeding with any upgrade.
- 2. Upgrade Discourse to the latest stable/beta/tests-passed branch (version greater than 3.1.0) which contains the security patch.
- 3. After upgrading, verify the patch is applied by reviewing the Discourse security release notes for 3.1.1 or later.
- 4. If unable to upgrade immediately: navigate to your Discourse admin panel and ensure CSP (Content Security Policy) is enabled and set to the default Discourse configuration.
- 5. In admin settings, review and remove any 'embeddable hosts' that are not explicitly required for your community functionality.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-29196 — 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-2023-29196 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
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- 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