GHSA-g6gw-c38x-mqfc is a medium-severity (CVSS 5.3) Uncontrolled Resource Consumption vulnerability in hono. O3 Security confirms whether GHSA-g6gw-c38x-mqfc is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Hono: Unbounded dot-notation nesting in `parseBody()` can cause memory exhaustion
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- 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-g6gw-c38x-mqfc.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
hononpmDescription
Summary
When parseBody() expands dot-separated form field names into nested objects, it does not limit the nesting depth or the total number of objects created. A request body well within a normal size limit can therefore allocate an object graph far larger than the request itself, and concurrent requests can exhaust the heap and terminate the process.
Details
Each dot-separated segment of a field name creates an intermediate object. Neither the segments within a single field name nor the total across a request was bounded, and empty segments were preserved, so a field name could encode one nesting level per byte.
Both shapes produce the effect: a single deeply dotted field name, and a large number of shallowly dotted ones within one body. A request body size limit does not prevent it, because the amplification happens after the body has been accepted.
Dot-notation parsing is not enabled by default.
Impact
An attacker who can reach an endpoint that parses request bodies with dot-notation enabled can send concurrent requests whose memory cost is disproportionate to their size.
This may lead to:
- exhaustion of the JavaScript heap and termination of the server process
- the service remaining unavailable until it is restarted
This issue affects applications that explicitly enable dot-notation parsing. Applications using the default behaviour are not affected.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | hono | all versions | 4.13.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for hono. 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 hono to 4.13.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-g6gw-c38x-mqfc 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-g6gw-c38x-mqfc 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-g6gw-c38x-mqfc. 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-g6gw-c38x-mqfc in your dependencies?
O3 detects GHSA-g6gw-c38x-mqfc across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.