GHSA-6w86-wgwq-rgq8
neqo-qpack has iInteger overflow in qpack dynamic table indexing
Blast Radius
neqo-qpackReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
Summary
An unsanitized qpack index can lead to an integer overflow, panicing in debug mode, accessing the wrong or no dynamic table entry in release mode.
What does this mean for Firefox? Firefox runs Neqo in release mode. A malicious remote can cause its own QUIC connection to fail to use qpack, i.e. compression, or enter an inconsistent state. The remote can not crash Firefox, nor affect other QUIC connections.
Details
See fuzz report in https://github.com/mozilla/neqo/issues/3406.
PoC
See test in pull request.
Impact
All Firefox users. Though vulnerability likely scoped to same connection, i.e. low impact.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | neqo-qpack | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for neqo-qpack. 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.
Remediation status
No patched version of neqo-qpack has shipped for GHSA-6w86-wgwq-rgq8 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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-6w86-wgwq-rgq8 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-6w86-wgwq-rgq8. 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-6w86-wgwq-rgq8 in your dependencies?
O3 detects GHSA-6w86-wgwq-rgq8 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.