CVE-2026-63202

BinaryHttpParser: Unauthenticated CPU-exhaustion DoS via infinite loop in field-section decoding - ID: BHTTP-LOOP-001 - Severity: High - CVSS v3.1: 7.5 — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CWE: CWE-835 (Loop with Unreachable Exit Condition) — secondary CWE-400 (Uncontrolled Resource Consumption) - Affected component: codec-bhttp → io.netty.incubator.codec.bhttp.BinaryHttpParser#readFieldSection, file codec-bhttp/src/main/java/io/netty/incubator/codec/bhttp/BinaryHttpParser.java:619-626 - Affected version: netty-incubator-codec-ohttp HEAD d3f2b49 (release 0.0.22.Final + 3 commits). The loop has existed since the parser was introduced and is present in the latest code; all published advisory fixes are already applied. - Reachable from: io.netty.incubator.codec.ohttp.OHttpRequestResponseContext$ContentDecoder#decodeChunk (codec-ohttp/.../OHttpRequestResponseContext.java:214), i.e. the auto-wired OHTTP server and client codecs. - Confidence: High (empirically reproduced hang + thread dump against the unmodified parser). Summary BinaryHttpParser decodes Binary HTTP (RFC 9292) messages. An OHTTP gateway/client built on this library feeds the decrypted OHTTP body straight into BinaryHttpParser.parse(...). The field-section decoding loop terminates only on the exact condition fieldSectionLength != 0 and relies on a Java assert to guarantee forward progress. Because (a) the loop counter can be driven negative and (b) readFieldLine(...) legitimately consumes zero bytes and returns null on a truncated/over-long field line, the loop can spin forever. Assertions are disabled in any normal production JVM, so the two assert statements meant to catch this provide no protection. A single ~17-byte Binary HTTP message — encapsulated by an unauthenticated attacker inside a normal OHTTP request, using the gateway's public key configuration — pins one Netty event-loop thread at 100% CPU permanently. A handful of such requests exhausts the entire event-loop group and takes

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