CVE-2026-93565: Io.netty/netty-codec-http: netty rtspdecoder method-token smuggling via trailing control byte

Summary RtspMethods.valueOf() silently strips trailing control bytes (any character with code point <= 0x20, the full range that String.trim() removes) before performing a cache lookup against its ten pre-populated method constants. A wire-delivered RTSP request whose method token ends with a trailing control byte — for example PLAY\x00 or PLAY\r, immediately before the separating space — is decoded by RtspDecoder as a fully successful PLAY request, with decoderResult().isSuccess() == true and request.method() == RtspMethods.PLAY (same object reference as the cached singleton). The application layer cannot distinguish this from a clean PLAY request. This is the same root cause as #16723 and #16971, in a sibling that those fixes did not reach. The fix for HttpMethod hardened HttpMethod.valueOf() directly, but RtspMethods.valueOf() has its own independent checkNonEmptyAfterTrim() call that runs before the cache lookup — meaning a trailing-control-byte token hits the cache before the hardened HttpMethod constructor ever sees it. Reproduction Minimal wire-level reproduction Send the following raw bytes to any Netty-based RTSP server using R