CVE-2025-48954
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 discussion platform. Versions prior to 3.5.0.beta6 are vulnerable to cross-site scripting when the content security policy isn't enabled when using social logins. Version 3.5.0.beta6 patches the issue. As a workaround, have the content security policy enabled.
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 versions prior to 3.5.0.beta6 contain a cross-site scripting vulnerability in the social login flow when Content Security Policy is not enabled, allowing attackers to inject malicious scripts.
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< 3.5.0= 3.5.0CVSS 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 installed Discourse versionNavigate to Admin panel > About page or use the /about endpoint. Alternatively, check the version file in your Discourse installation directory if you have CLI access.Affected if Version is less than 3.5.0 or equals exactly 3.5.0
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Verify Content Security Policy statusGo to Admin panel > Settings > Security > content_security_policy. Confirm whether the policy is enabled (enabled: true) or check if the content_security_policy site setting is turned on.Affected if Content Security Policy is disabled or not configured
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Confirm social login is configuredCheck Admin panel > Settings > Login. Look for enabled social login providers such as Google, Facebook, GitHub, or other OAuth2 connectors.Affected if At least one social login provider is enabled and configured
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Review CSP report-only modeCheck if content_security_policy_report_only is set to true in the security settings. This mode logs violations but does not enforce protection.Affected if CSP is in report-only mode only (not actively enforcing)
Environment is affected if running Discourse version 3.5.0 or earlier AND Content Security Policy is disabled or not enforcing, AND social login providers are configured.
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 · scoped3.5.0
Enable Content Security Policy in Discourse settings, or upgrade to version 3.5.0.beta6 or later which contains the security patch.
3.5.0.beta6 or newer stable release
- Upgrade Discourse to version 3.5.0.beta6 or later to resolve the XSS vulnerability
- As an alternative mitigation, enable the content security policy in your Discourse configuration if immediate upgrade is not feasible
- After upgrading or enabling CSP, verify that social login functionality works correctly
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 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 $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-48954 — 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-2025-48954 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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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