Vulnerability Description
Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final through 4.2.15.Final and 4.1.0.Final through 4.1.135.Final, the `SpdyHttpDecoder` handler in Netty's SPDY-to-HTTP codec allocates a pooled `ByteBuf` when processing a client-initiated `SYN_STREAM` frame with `FLAG_FIN=0` and stores the partially constructed `FullHttpRequest` in `messageMap`; when the remote peer sends `RST_STREAM` for that stream or the accumulated content exceeds `maxContentLength`, the decoder removes the entry but does not release the pooled `ByteBuf`, causing native memory exhaustion. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Netty | Netty | >= 4.1.0, < 4.1.136 |
Related Weaknesses (CWE)
References
- https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003bPatch
- https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6Patch
- https://github.com/netty/netty/releases/tag/netty-4.1.136.FinalRelease Notes
- https://github.com/netty/netty/releases/tag/netty-4.2.16.FinalRelease Notes
- https://github.com/netty/netty/security/advisories/GHSA-jppx-w49h-x2qqVendor Advisory
FAQ
What is CVE-2026-56745?
CVE-2026-56745 is a vulnerability with a CVSS score of 7.5 (HIGH). Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final through 4.2.15.Final and 4.1.0.Final through 4.1.135.Final, the `SpdyHttpDecoder` hand...
How severe is CVE-2026-56745?
CVE-2026-56745 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-56745?
Check the references section above for vendor advisories and patch information. Affected products include: Netty Netty.