GHSA-6qf2-7x63-mm6v
GHSA-6qf2-7x63-mm6v is a Improper Input Validation vulnerability in matrix-synapse. O3 Security confirms whether GHSA-6qf2-7x63-mm6v is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Synapse pagination Denial of Service
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-6qf2-7x63-mm6v.
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.
Real-World Exposure
matrix-synapseReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Impact
In federated rooms, malicious homeservers can craft room events in such a way that prevents Synapse from providing full history to paginating clients.
Clients could therefore fail to display room history.
Patches
Update to Synapse 1.152.1 or later.
Workarounds
There are no known workarounds for this issue.
Identifiers
- ELEMENTSEC-2025-1636
For more information
If you have any questions or comments about this advisory, please email us at security at element.io.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | matrix-synapse | all versions | 1.152.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for matrix-synapse. 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-synapse to 1.152.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6qf2-7x63-mm6v 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-6qf2-7x63-mm6v 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-6qf2-7x63-mm6v. 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-6qf2-7x63-mm6v in your dependencies?
O3 detects GHSA-6qf2-7x63-mm6v across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.