What is GHSA-6W86-WGWQ-RGQ8?

GHSA-6W86-WGWQ-RGQ8 is a medium-severity integer overflow or wraparound vulnerability in neqo-qpack (rust), affecting versions <= 0.22.2. No fixed version is listed yet. An arithmetic operation produces a value that exceeds the integer type's maximum, causing it to wrap to an unexpected small value.

Which versions of neqo-qpack are affected by GHSA-6W86-WGWQ-RGQ8?

neqo-qpack (rust) versions <= 0.22.2 is affected.

Is there a fix for GHSA-6W86-WGWQ-RGQ8?

No fixed version is listed for GHSA-6W86-WGWQ-RGQ8 yet. Monitor the advisory for updates and apply mitigations in the interim.

Is GHSA-6W86-WGWQ-RGQ8 exploitable, and should I be worried?

Whether GHSA-6W86-WGWQ-RGQ8 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

What actually determines whether GHSA-6W86-WGWQ-RGQ8 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

GHSA-6W86-WGWQ-RGQ8 in neqo-qpack

Q: Which versions of neqo-qpack are affected by GHSA-6W86-WGWQ-RGQ8?

neqo-qpack (rust) versions <= 0.22.2 is affected.

Q: Is there a fix for GHSA-6W86-WGWQ-RGQ8?

No fixed version is listed for GHSA-6W86-WGWQ-RGQ8 yet. Monitor the advisory for updates and apply mitigations in the interim.

Q: Is GHSA-6W86-WGWQ-RGQ8 exploitable, and should I be worried?

Whether GHSA-6W86-WGWQ-RGQ8 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

Q: What actually determines whether GHSA-6W86-WGWQ-RGQ8 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

Q: How do I fix GHSA-6W86-WGWQ-RGQ8?

No fixed version is listed yet. In the interim: Keep the dependency up to date. In native-code projects, use checked arithmetic or integer types that enforce bounds.

Summary

neqo-qpack has iInteger overflow in qpack dynamic table indexing

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.

An arithmetic operation produces a value that exceeds the integer type's maximum, causing it to wrap to an unexpected small value. Typical impact: incorrect size calculations leading to heap overflows or logic errors.

Affected versions

neqo-qpack (<= 0.22.2)

Security releases

Not available

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

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Remediation advice

No fixed version is listed for GHSA-6W86-WGWQ-RGQ8 yet.

In the interim: Keep the dependency up to date. In native-code projects, use checked arithmetic or integer types that enforce bounds.

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently Asked Questions

What is GHSA-6W86-WGWQ-RGQ8? GHSA-6W86-WGWQ-RGQ8 is a medium-severity integer overflow or wraparound vulnerability in neqo-qpack (rust), affecting versions <= 0.22.2. No fixed version is listed yet. An arithmetic operation produces a value that exceeds the integer type's maximum, causing it to wrap to an unexpected small value.
Which versions of neqo-qpack are affected by GHSA-6W86-WGWQ-RGQ8? neqo-qpack (rust) versions <= 0.22.2 is affected.
Is there a fix for GHSA-6W86-WGWQ-RGQ8? No fixed version is listed for GHSA-6W86-WGWQ-RGQ8 yet. Monitor the advisory for updates and apply mitigations in the interim.
Is GHSA-6W86-WGWQ-RGQ8 exploitable, and should I be worried? Whether GHSA-6W86-WGWQ-RGQ8 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
What actually determines whether GHSA-6W86-WGWQ-RGQ8 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
How do I fix GHSA-6W86-WGWQ-RGQ8? No fixed version is listed yet. In the interim: Keep the dependency up to date. In native-code projects, use checked arithmetic or integer types that enforce bounds.