How severe is GHSA-5x3r-wrvg-rp6q?

GHSA-5x3r-wrvg-rp6q has a CVSS score of 5.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-5x3r-wrvg-rp6q?

GHSA-5x3r-wrvg-rp6q affects the following packages: io.netty:netty-codec-http2 (Maven), io.netty:netty-codec-http2 (Maven). Ecosystems affected: Maven.

How do I fix GHSA-5x3r-wrvg-rp6q?

Update io.netty:netty-codec-http2 to 4.2.15.Final or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5x3r-wrvg-rp6q is resolved across your whole dependency graph.

How do I detect GHSA-5x3r-wrvg-rp6q in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.netty:netty-codec-http2. 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.

How do I mitigate GHSA-5x3r-wrvg-rp6q 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-5x3r-wrvg-rp6q?

O3 pinpoints whether GHSA-5x3r-wrvg-rp6q is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-5x3r-wrvg-rp6q actively exploited in the wild?

No public exploit code has been indexed for GHSA-5x3r-wrvg-rp6q 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.

What is the EPSS score for GHSA-5x3r-wrvg-rp6q?

GHSA-5x3r-wrvg-rp6q has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 21th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-5x3r-wrvg-rp6q?

GHSA-5x3r-wrvg-rp6q is classified as Uncontrolled Resource Consumption (CWE-400). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-5x3r-wrvg-rp6q published, and has it been updated?

GHSA-5x3r-wrvg-rp6q was published on June 8, 2026 and was last updated on June 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕ Maven

GHSA-5x3r-wrvg-rp6q

MEDIUM

Netty HTTP/2: Advertised MAX_CONCURRENT_STREAMS are not enforced

Also known asCVE-2026-47244

Published

Jun 8, 2026

Updated

Jun 12, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk21th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

2 pkgs affected

☕io.netty:netty-codec-http2☕io.netty:netty-codec-http2

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Impact

DefaultHttp2Connection.DefaultEndpoint initialises maxActiveStreams/maxStreams to Integer.MAX_VALUE, and Http2Settings never inserts SETTINGS_MAX_CONCURRENT_STREAMS by default (Http2Settings.java:305-307 only clamps a user-supplied value). Unless the application explicitly calls initialSettings().maxConcurrentStreams(n), a Netty HTTP/2 server advertises no limit and enforces none locally. Each open stream allocates a DefaultStream object, PropertyMap slots, flow-controller state and IntObjectHashMap entry; with ~2^30 permissible odd stream IDs a single TCP connection can create hundreds of thousands of long-lived stream objects. This is also the precondition for CVE-2023-44487-style Rapid-Reset amplification, where the absence of a low concurrent cap multiplies backend work.

Resources

https://www.rfc-editor.org/rfc/rfc7540.html#section-6.5.2

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`io.netty:netty-codec-http2`	≥ 4.2.0.Final&&< 4.2.15.Final	4.2.15.Final
☕Maven	`io.netty:netty-codec-http2`	all versions	4.1.135.Final

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.netty:netty-codec-http2. 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.
Fix
Update io.netty:netty-codec-http2 to 4.2.15.Final or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5x3r-wrvg-rp6q is resolved across your whole dependency graph.
Workarounds
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-5x3r-wrvg-rp6q 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-5x3r-wrvg-rp6q. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact DefaultHttp2Connection.DefaultEndpoint initialises maxActiveStreams/maxStreams to Integer.MAX_VALUE, and Http2Settings never inserts SETTINGS_MAX_CONCURRENT_STREAMS by default (Http2Settings.java:305-307 only clamps a user-supplied value). Unless the application explicitly calls initialSettings().maxConcurrentStreams(n), a Netty HTTP/2 server advertises no limit and enforces none locally. Each open stream allocates a DefaultStream object, PropertyMap slots, flow-controller state and IntObjectHashMap entry; with ~2^30 permissible odd stream IDs a single TCP connection can create hund

O3 Security · Impact-Aware SCA

Is GHSA-5x3r-wrvg-rp6q in your dependencies?

O3 detects GHSA-5x3r-wrvg-rp6q across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works