GHSA-mh74-4m5g-fcjx
MEDIUMGHSA-mh74-4m5g-fcjx is a medium-severity (CVSS 5.3) Improper Input Validation vulnerability in matrix-sydent. O3 Security confirms whether GHSA-mh74-4m5g-fcjx is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Malicious users could abuse Sydent to control the content of invitation emails
Blast Radius
matrix-sydentReal-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
A malicious user could abuse Sydent to send out arbitrary emails from the Sydent email address. This could be used to construct plausible phishing emails, for example.
Patches
Fixed in 4469d1d, 6b405a8, 65a6e91.
Note that these patches include changes to the default email templates. If these templates have been locally modified, they must also be updated.
For more information
If you have any questions or comments about this advisory, email us at [email protected].
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | matrix-sydent | all versions | 2.3.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for matrix-sydent. 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-sydent to 2.3.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mh74-4m5g-fcjx 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-mh74-4m5g-fcjx 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-mh74-4m5g-fcjx. 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-mh74-4m5g-fcjx in your dependencies?
O3 detects GHSA-mh74-4m5g-fcjx across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.