github.com/apernet/hysteria

GHSA-JQC5-2P7Q-FQFC

GHSA-JQC5-2P7Q-FQFC is a high-severity allocation of resources without limits or throttling vulnerability in github.com/apernet/hysteria (go), affecting versions < 2.9.2. It is fixed in 2.9.2.

Key facts
CVSS score
7.5
High
Attack vector
Network
Issuing authority
GitHub Advisory Database
Affected package
github.com/apernet/hysteria
Fixed in
2.9.2
Disclosed
Not available

Summary

Summary Sending an excessively large header by an attacker could lead to a server-side DoS attack. Details The current sniff implementation does not explicitly specify the upper limit for HTTP headers. Attackers can continuously send excessively large headers without including \r\n\r\n, leading to ServerDoS and OutOfMemory errors. PoC server.yaml poc.sh poc.go Impact Testing showed that the server side used a maximum of 16GB. Server memory DoS and may cause OOM.

Impact

What is allocation of resources without limits or throttling?

The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap. Typical impact: resource exhaustion leading to denial of service.

Severity and exposure

GHSA-JQC5-2P7Q-FQFC has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.

A fixed version is available (2.9.2). Upgrading removes the vulnerable code path.

Affected versions

go

  • github.com/apernet/hysteria (< 2.9.2)

Security releases

  • github.com/apernet/hysteria → 2.9.2 (go)
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 instead of chasing every advisory.

Kodem's runtime-powered SCA identifies whether GHSA-JQC5-2P7Q-FQFC is reachable in your applications. Explore open-source security for your team.

See if GHSA-JQC5-2P7Q-FQFC is reachable in your applications. Get a demo

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Remediation advice

Upgrade github.com/apernet/hysteria to 2.9.2 or later to resolve this vulnerability.

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

Frequently asked questions about GHSA-JQC5-2P7Q-FQFC

What is GHSA-JQC5-2P7Q-FQFC?

GHSA-JQC5-2P7Q-FQFC is a high-severity allocation of resources without limits or throttling vulnerability in github.com/apernet/hysteria (go), affecting versions < 2.9.2. It is fixed in 2.9.2. The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap.

How severe is GHSA-JQC5-2P7Q-FQFC?

GHSA-JQC5-2P7Q-FQFC has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which versions of github.com/apernet/hysteria are affected by GHSA-JQC5-2P7Q-FQFC?

github.com/apernet/hysteria (go) versions < 2.9.2 is affected.

Is there a fix for GHSA-JQC5-2P7Q-FQFC?

Yes. GHSA-JQC5-2P7Q-FQFC is fixed in 2.9.2. Upgrade to this version or later.

Is GHSA-JQC5-2P7Q-FQFC exploitable, and should I be worried?

Whether GHSA-JQC5-2P7Q-FQFC 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-JQC5-2P7Q-FQFC 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-JQC5-2P7Q-FQFC?

Upgrade github.com/apernet/hysteria to 2.9.2 or later.

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