GHSA-3mwq-h3g6-ffhm
MEDIUMVapor's incorrect request error handling triggers server crash
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
github.com/vapor/vaporReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects SwiftURL packages — download data is not available via public APIs for these ecosystems.
Description
Vapor incorrectly handles errors encountered during parsing of HTTP 1.x requests, triggering a precondition failure in swift-nio due to API misuse and causing immediate termination of the server process.
Impact
This is a denial of service vulnerability, impacting all users of affected versions of Vapor. Because the crash is an explicit assertion failure, there is no corruption of process state and no risk of data leakage or unauthorized code execution. Total impact is limited to an immediately recoverable service interruption.
Patches
The issue is fixed as of Vapor release 4.84.2.
Workarounds
None known at this time.
For more information
If you have any questions or comments about this advisory:
- Open an issue in the Vapor repo
- Ask in Vapor Discord
Acknowledgements
Full credit for reporting this issue goes to @t0rchwo0d, with additional thanks for responsibly disclosing.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦SwiftURL | github.com/vapor/vapor | ≥ 4.83.2&&< 4.84.2 | 4.84.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/vapor/vapor. 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 github.com/vapor/vapor to 4.84.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-3mwq-h3g6-ffhm 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-3mwq-h3g6-ffhm 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-3mwq-h3g6-ffhm. 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-3mwq-h3g6-ffhm in your dependencies?
O3 detects GHSA-3mwq-h3g6-ffhm across SwiftURL dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.