How severe is GHSA-6w86-wgwq-rgq8?

No CVSS score has been assigned to GHSA-6w86-wgwq-rgq8 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-6w86-wgwq-rgq8?

GHSA-6w86-wgwq-rgq8 affects the following packages: neqo-qpack (crates.io). Ecosystems affected: crates.io.

How do I fix GHSA-6w86-wgwq-rgq8?

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.

How do I detect GHSA-6w86-wgwq-rgq8 in my crates.io dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for neqo-qpack, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-6w86-wgwq-rgq8 if there is no patch (or I can't update yet)?

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 does O3 Security protect against GHSA-6w86-wgwq-rgq8?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-6w86-wgwq-rgq8 can be triaged on real exposure rather than presence alone.

Is GHSA-6w86-wgwq-rgq8 actively exploited in the wild?

No public exploit code has been indexed for GHSA-6w86-wgwq-rgq8 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was GHSA-6w86-wgwq-rgq8 published, and has it been updated?

GHSA-6w86-wgwq-rgq8 was published on March 4, 2026 and was last updated on March 4, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🦀 crates.io

Not in CISA KEV

GHSA-6w86-wgwq-rgq8 — neqo-qpack

GHSA-6w86-wgwq-rgq8 is a remote code execution vulnerability in neqo-qpack. No vendor fix is recorded yet; mitigation options are listed below.

neqo-qpack has iInteger overflow in qpack dynamic table indexing

Published

Mar 4, 2026

Updated

Mar 4, 2026

Affected

1 pkg

Patched

None yet

Exploits

None indexed

Exploitation data as of Mar 4, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

🦀neqo-qpack

Real-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

1 total

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`neqo-qpack`	all versions	No fix

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for neqo-qpack, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-6w86-wgwq-rgq8 can be triaged on real exposure rather than presence alone.

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

### 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 scop

O3 Security · Impact-Aware SCA

Is GHSA-6w86-wgwq-rgq8 in your dependencies?

O3 Security finds GHSA-6w86-wgwq-rgq8 across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works