netty-incubator-codec-ohttp's Incorrect Native Pointer Derivation in Pooled Direct ByteBuf Fallback Leads to Out-of-Bounds Native Memory Access

CVE-2026-48040

What is CVE-2026-48040?

The netty incubator codec.bhttp is a java language binary http parser. The library implements Oblivious HTTP (RFC 9458) using BoringSSL's HPKE C library via JNI. When deriving native memory addresses for cryptographic operations versions prior to 0.0.22.Final provide a fallback path for direct ByteBufs that do not expose their memory address through hasMemoryAddress(). This fallback occurs when sun.misc.Unsafe is unavailable to Netty — for example, when the JVM is started with -Dio.netty.noUnsafe=true, when a SecurityManager restricts Unsafe access, or when running on non-HotSpot JVMs. In these configurations, Netty's default PooledByteBufAllocator returns PooledDirectByteBuf instances for which hasMemoryAddress() returns false. Under the enabling JVM configuration, an unauthenticated network attacker can cause the OHTTP gateway to corrupt memory belonging to other concurrent connections and disclose the contents of adjacent pooled direct buffers by triggering cryptographic operations with crafted OHTTP requests. The corruption occurs regardless of whether the AEAD tag verification succeeds, as BoringSSL zeroizes the output buffer on failure. The information disclosure path provides the attacker with the encryption key needed to extract the leaked data. This violates the confidentiality and integrity of all connections sharing the same Netty buffer arena. Version 0.0.22.Final fixes the issue.

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