GHSA-whhv-gg5v-864r
HIGHQwik City has array method pollution in FormData processing allows type confusion and DoS
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.
@builder.io/qwik-citynpmDescription
Summary
Qwik City improperly inferred arrays from dotted form field names during FormData parsing. By submitting mixed array-index and object-property keys for the same path, an attacker could cause user-controlled properties to be written onto values that application code expected to be arrays.
Description
When processing application/x-www-form-urlencoded or multipart/form-data requests, Qwik City converted dotted field names such as items.0 and items.1 into nested structures. If a path was interpreted as an array, additional attacker-controlled keys on the same path, such as items.toString, items.push, items.valueOf, or items.length, could alter the resulting server-side value in unexpected ways.
Applications that assumed these parsed values were safe arrays could be affected. Depending on application behavior, this could lead to request handling failures, denial of service through malformed array state or oversized lengths, and type confusion in downstream code.
This issue affects form parsing in Qwik City request handling. It does not require authentication if the vulnerable route is publicly reachable.
Impact
An attacker can send crafted form submissions that cause parsed input to differ from the application’s expected shape. Possible outcomes include:
- Triggering runtime errors when application code calls array methods on attacker-influenced values
- Inflating array length or otherwise creating malformed structures that increase server work or memory use
- Causing type confusion in application logic that trusts parsed form data to be a normal array
There is no direct evidence that this issue enables confidentiality or integrity impact by itself; the primary risk is denial of service and application instability.
Patched Versions
Patched in 1.19.2.
Workarounds
Until patched, avoid trusting parsed form data to be a well-formed array when using dotted field names, and validate or normalize action input before using array methods or relying on array shape.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @builder.io/qwik-city | all versions | 1.19.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @builder.io/qwik-city. 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 @builder.io/qwik-city to 1.19.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-whhv-gg5v-864r 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-whhv-gg5v-864r 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-whhv-gg5v-864r. 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-whhv-gg5v-864r in your dependencies?
O3 detects GHSA-whhv-gg5v-864r across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.