GHSA-rfv9-x7hh-xc32
HIGHmatrix-js-sdk Prototype Pollution vulnerability
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
matrix-js-sdknpmDescription
Impact
Events sent with special strings in key places can temporarily disrupt or impede the matrix-js-sdk from functioning properly, potentially impacting the consumer's ability to process data safely. Note that the matrix-js-sdk can appear to be operating normally but be excluding or corrupting runtime data presented to the consumer.
Patches
This is fixed in matrix-js-sdk 19.4.0.
Workarounds
Redacting applicable events, waiting for the sync processor to store data, and restarting the client can often fix it. Alternatively, redacting the applicable events and clearing all storage will often fix most perceived issues.
In some cases, no workarounds are possible.
References
https://learn.snyk.io/lessons/prototype-pollution/javascript/
For more information
If you have any questions or comments about this advisory please email us at security at matrix.org.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | matrix-js-sdk | all versions | 19.4.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for matrix-js-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-js-sdk to 19.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-rfv9-x7hh-xc32 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 GHSA-rfv9-x7hh-xc32 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 GHSA-rfv9-x7hh-xc32. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-rfv9-x7hh-xc32 in your dependencies?
O3 detects GHSA-rfv9-x7hh-xc32 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.