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 per