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?

The records we use list no patched version of neqo-qpack for GHSA-6w86-wgwq-rgq8. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.

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)?

Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

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

neqo-qpack has iInteger overflow in qpack dynamic table indexingGHSA-6w86-wgwq-rgq8

GHSA-6w86-wgwq-rgq8 is a remote code execution vulnerability in neqo-qpack. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.

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
The records we use list no patched version of neqo-qpack for GHSA-6w86-wgwq-rgq8. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.
Mitigate without a patch
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

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

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