Netty is a network application framework for development of protocol servers and clients. In netty-codec-http2 prior to versions 4.1.135.Final and 4.2.15.Final, the `DelegatingDecompressorFrameListener` class orchestrates HTTP/2 decompression by embedding a per-stream `EmbeddedChannel` that runs the appropriate decompression codec (gzip, deflate, zstd) and forwards decompressed chunks to a wrapped listener. Each decompressed chunk is a pooled `ByteBuf` handed to an anonymous `ChannelInboundHandlerAdapter` tail handler, which becomes the sole owner responsible for releasing it. A remote peer could send frames that would result in the flow-controller throwing and so trigger a resource leak which at the end might take down the whole JVM due OOME. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48043.json
https://github.com/netty/netty/security/advisories/GHSA-c2gf-v879-257j
https://github.com/netty/netty/releases/tag/netty-4.2.15.Final
https://github.com/netty/netty/releases/tag/netty-4.1.135.Final
https://bugzilla.redhat.com/show_bug.cgi?id=2488442
https://access.redhat.com/security/cve/CVE-2026-48043
https://access.redhat.com/errata/RHSA-2026:34608
https://access.redhat.com/errata/RHSA-2026:26586