CVE-2023-30609
MEDIUMCVE-2023-30609 is a medium-severity (CVSS 5.4) CWE-74 vulnerability in matrix-react-sdk. O3 Security confirms whether CVE-2023-30609 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
matrix-react-sdk vulnerable to HTML injection in search results via plaintext message highlighting
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
matrix-react-sdknpmDescription
matrix-react-sdk is a react-based SDK for inserting a Matrix chat/VoIP client into a web page. Prior to version 3.71.0, plain text messages containing HTML tags are rendered as HTML in the search results. To exploit this, an attacker needs to trick a user into searching for a specific message containing an HTML injection payload. No cross-site scripting attack is possible due to the hardcoded content security policy. Version 3.71.0 of the SDK patches over the issue. As a workaround, restarting the client will clear the HTML injection.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | matrix-react-sdk | all versions | 3.71.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for matrix-react-sdk. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update matrix-react-sdk to 3.71.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-30609 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2023-30609 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2023-30609. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-30609 in your dependencies?
O3 detects CVE-2023-30609 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.