GHSA-5x3r-wrvg-rp6q
Netty HTTP/2: Advertised MAX_CONCURRENT_STREAMS are not enforced
At a glance
- Published
- Updated
- CVE
- CVE-2026-47244
- CVSS_V3
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
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
| Package | Versions |
|---|---|
| Maven · io.netty:netty-codec-http2 | introduced 4.2.0.Final, fixed 4.2.15.Final |
| Maven · io.netty:netty-codec-http2 | introduced 0, fixed 4.1.135.Final |
References
- https://github.com/netty/netty/security/advisories/GHSA-5x3r-wrvg-rp6q WEB
- https://nvd.nist.gov/vuln/detail/CVE-2026-47244 ADVISORY
- https://github.com/netty/netty PACKAGE
- https://github.com/netty/netty/releases/tag/netty-4.1.135.Final WEB
- https://github.com/netty/netty/releases/tag/netty-4.2.15.Final WEB
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — GitHub Advisory Database |