CVE-2026-56745
HIGHNetty SpdyHttpDecoder: ByteBuf Reference Leak on RST_STREAM Leads to Native Memory Exhaustion
Title source: cnaDescription
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.
References (5)
Core 5
Core References
X_Refsource_Confirm x_refsource_confirm
https://github.com/netty/netty/security/advisories/GHSA-jppx-w49h-x2qq
X_Refsource_Misc x_refsource_misc
https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b
X_Refsource_Misc x_refsource_misc
https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6
X_Refsource_Misc x_refsource_misc
https://github.com/netty/netty/releases/tag/netty-4.1.136.Final
X_Refsource_Misc x_refsource_misc
https://github.com/netty/netty/releases/tag/netty-4.2.16.Final
Scores
CVSS v3
7.5
EPSS
0.0050
EPSS Percentile
40.2%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-400
Status
published
Products (5)
io.netty/netty-codec-http
4.1.0.Final - 4.1.136.FinalMaven
io.netty/netty-codec-http
4.2.0.Final - 4.2.16.FinalMaven
netty/netty
4.1.0 - 4.1.136
netty/netty
>= 4.1.0.Final, < 4.1.136.Final
netty/netty
>= 4.2.0.Final, < 4.2.16.Final
Published
Jul 21, 2026
Tracked Since
Jul 22, 2026