CVE-2026-50560
Netty is a network application framework for development of protocol servers and clients.
Impact
Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty HTTP/2 max header size handling produces an attack similar to HTTP/2 Rapid Reset. There is a setting in the http2 specification called `SETTINGS_MAX_HEADER_LIST_SIZE`. When a client sends that setting to Netty, it appears that Netty will behave as follows: read the request; proxy the request to the origin; attempt to produce a response; and create an exception while writing the headers for the response. Functionally, this should be similar to the http2 reset attack, but with a different on-the-wire signature. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| maven | io.netty:netty-codec-http2 | >= 4.2.0.Final, <= 4.2.14.Final | 4.2.15.Final |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Netty | Netty | before 4.1.135 from 4.2.0 before 4.2.15 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-563q-j3cm-6jxm
- https://github.com/netty/netty/security/advisories/GHSA-563q-j3cm-6jxm
- https://nvd.nist.gov/vuln/detail/CVE-2026-50560
- https://github.com/netty/netty/releases/tag/netty-4.1.135.Final
- https://github.com/netty/netty/releases/tag/netty-4.2.15.Final
- https://www.rfc-editor.org/rfc/rfc9113.html#name-defined-settings