Netty: [SpdyHttpDecoder] ByteBuf Reference Leak on RST_STREAM Leads to Native Memory Exhaustion
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`, storing the partially-constructed `FullHttpRequest` in an internal map (`messageMap`) to accumulate subsequent `DATA` frames. When the remote peer sends an `RST_STREAM` for that stream, or when the accumulated content exceeds `maxContentLength`, the decoder removes the entry from the map but **never releases the pooled ByteBuf**, permanently leaking the allocated memory.
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-56745US | high7.5 | — | ||
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 `S… | ||||
references
External citations — patches, advisories, analysis.
- https://github.com/netty/nettyPACKAGE
- https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003bWEB
- https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6WEB
- https://github.com/netty/netty/releases/tag/netty-4.1.136.FinalWEB
- https://github.com/netty/netty/releases/tag/netty-4.2.16.FinalWEB
- https://github.com/netty/netty/security/advisories/GHSA-jppx-w49h-x2qqWEB
- https://nvd.nist.gov/vuln/detail/CVE-2026-56745ADVISORY
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