high7.5
CVE-2026-55831
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 4.1.136.Final and 4.2.16.Final, Netty's SPDY SETTINGS decoder accepts a peer-declared SETTINGS entry count up to the 24-bit frame-length limit and materializes every unique setting ID in `DefaultSpdySettingsFrame`, allowing a remote SPDY/3.1 peer to send a syntactically valid roughly 2 MiB SETTINGS frame that creates 262144 map entries and amplifies network input into heap growth and ordered-map insertion work. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| maven | io.netty:netty-codec-http | >= 4.2.0.Final, <= 4.2.15.Final | 4.2.16.Final |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Netty | Netty | from 4.1.0 before 4.1.136 from 4.2.0 before 4.2.16 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-6jqx-86gh-f27w
- https://github.com/netty/netty/security/advisories/GHSA-6jqx-86gh-f27w
- https://nvd.nist.gov/vuln/detail/CVE-2026-55831
- https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b
- https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6
- https://github.com/netty/netty/releases/tag/netty-4.1.136.Final
- https://github.com/netty/netty/releases/tag/netty-4.2.16.Final