GHSA-624g-8qjg-8qxf
HIGHGHSA-624g-8qjg-8qxf is a high-severity (CVSS 8.6) CWE-1321 vulnerability in @conform-to/dom. O3 Security confirms whether GHSA-624g-8qjg-8qxf is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Conform contains a Prototype Pollution Vulnerability in `parseWith...` function
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
@conform-to/domnpm@conform-to/zodnpm@conform-to/yupnpmDescription
Summary
Conform allows the parsing of nested objects in the form of object.property. Due to an improper implementation of this feature, an attacker can exploit it to trigger prototype pollution by passing a crafted input to parseWith... functions.
PoC
const { parseWithZod } = require('@conform-to/zod');
const { z } = require("zod");
const param = new URLSearchParams("__proto__.pollution=polluted");
const schema = z.object({ "a": z.string() });
parseWithZod(param, { schema });
console.log("pollution:", ({}).pollution); // should print "polluted"
Details
The invocation of the parseWithZod function in the above PoC triggers the setValue function through getSubmissionContext and parse, executing the following process, resulting in prototype pollution:
let pointer = value;
pointer.__proto__ = pointer.__proto__;
pointer = pointer.__proto__;
pointer.polluted = "polluted";
This is caused by the lack of object existence checking on line 117 in formdata.ts, where the code only checks for the presence of pointer[key] without proper validation.
Impact
Applications that use conform for server-side validation of form data or URL parameters are affected by this vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @conform-to/dom | ≥ 1.0.0&&< 1.1.1 | 1.1.1 |
| 📦npm | @conform-to/zod | ≥ 1.0.0&&< 1.1.1 | 1.1.1 |
| 📦npm | @conform-to/yup | ≥ 1.0.0&&< 1.1.1 | 1.1.1 |
| 📦npm | @conform-to/zod | all versions | 0.9.2 |
| 📦npm | @conform-to/yup | all versions | 0.9.2 |
| 📦npm | @conform-to/dom | all versions | 0.9.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @conform-to/dom. 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 @conform-to/dom to 1.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-624g-8qjg-8qxf 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-624g-8qjg-8qxf 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-624g-8qjg-8qxf. 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-624g-8qjg-8qxf in your dependencies?
O3 detects GHSA-624g-8qjg-8qxf across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.