GHSA-8mj7-wxmc-f424
Use after free in Neon external buffers
Blast Radius
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Description
Neon provides functionality for creating JavaScript ArrayBuffer (and the Buffer subtype) instances backed by bytes allocated outside of V8/Node. The JsArrayBuffer::external and JsBuffer::external did not require T: 'static prior to Neon 0.10.1. This allowed creating an externally backed buffer from types that may be freed while they are still referenced by a JavaScript ArrayBuffer.
The following example demonstrates use after free. It compiles on versions <0.10.1 and fails to compile afterward.
pub fn soundness_hole(mut cx: FunctionContext) -> JsResult<JsArrayBuffer> {
let mut data = vec![0u8, 1, 2, 3];
// Creating an external from `&mut [u8]` instead of `Vec<u8>` since there is a blanket impl
// of `AsMut<T> for &mut T`
let buf = JsArrayBuffer::external(&mut cx, data.as_mut_slice());
// `buf` is still holding a reference to `data`!
drop(data);
Ok(buf)
}
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | neon | ≥ 0.8.0&&< 0.10.1 | 0.10.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for neon. 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 neon to 0.10.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8mj7-wxmc-f424 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-8mj7-wxmc-f424 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-8mj7-wxmc-f424. 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-8mj7-wxmc-f424 in your dependencies?
O3 detects GHSA-8mj7-wxmc-f424 across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.