Netty

By the Year

In 2026 there have been 18 vulnerabilities in Netty with an average score of 6.8 out of ten. Last year, in 2025 Netty had 6 security vulnerabilities published. That is, 12 more vulnerabilities have already been reported in 2026 as compared to last year. However, the average CVE base score of the vulnerabilities in 2026 is greater by 0.81.

Recent Netty Security Vulnerabilities

CVE	Date	Vulnerability	Products
CVE-2026-48480	Jun 04, 2026	Netty Incubator Codec: OHTTP Chunk Sign Verification Flaw (pre-0.0.22.Final) The netty incubator codec.bhttp is a java language binary http parser. Prior to version 0.0.22.FInal, the codec-ohttp implementation of draft-ietf-ohai-chunked-ohttp does not verify that a cryptographically-signed final chunk was received before the outer HTTP body terminates. An on-path adversary (the OHTTP relay itself, or any MITM on the relaygateway or relayclient transport) can forward a prefix of a legitimate chunked-OHTTP messagecut at a non-final chunk boundaryand close the outer body cleanly, producing no decryption error and no exception in the receiving application. Version 0.0.22.Final fixes the issue.	Netty
CVE-2026-48040	Jun 04, 2026	Netty codec.bhttp OHTTP memory corruption 0.0.22.Final fixed 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.	Netty
CVE-2026-41207	Jun 04, 2026	Netty BHTTP 0.0.21.Final: Silent All-Zero HKDF Key in AEAD (CVE-2026-41207) The netty incubator codec.bhttp is a java language binary http parser. Prior to version 0.0.21.Final, HKDF_expand returns non-NULL on failure. The byte[] is filled with zeros and has no way to distinguish success from failure. Since this output is used as HKDF key material for the response AEAD, a failure silently produces an all-zero key. When EVP_HPKE_CTX_export fails it also returns an empty byte[] array filled with zeros. This byte[] feeds directly into OHttpCrypto.createResponseAEAD(...). A silent all-zero export secret would produce a deterministic, attacker-predictable AEAD key. Version 0.0.21.Final patches the issue.	Netty
CVE-2026-44248	May 13, 2026	Netty <4.2.13.Final/4.1.133.Final MQTT 5 Properties Buffering Resource Exhaustion Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, the MQTT 5 header Properties section is parsed and buffered before any message size limit is applied. Specifically, in MqttDecoder, the decodeVariableHeader() method is called before the bytesRemainingBeforeVariableHeader > maxBytesInMessage check. The decodeVariableHeader() can call other methods which will call decodeProperties(). Effectively, Netty does not apply any limits to the size of the properties being decoded. Additionally, because MqttDecoder extends ReplayingDecoder, Netty will repeatedly re-parse the enormous Properties sections and buffer the bytes in memory, until the entire thing parses to completion. This can cause high resource usage in both CPU and memory. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.	Netty
CVE-2026-42587	May 13, 2026	Netty 4.x HttpContentDecompressor OOM DoS via br, zstd, snappy bypass Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpContentDecompressor accepts a maxAllocation parameter to limit decompression buffer size and prevent decompression bomb attacks. This limit is correctly enforced for gzip and deflate encodings via ZlibDecoder, but is silently ignored when the content encoding is br (Brotli), zstd, or snappy. An attacker can bypass the configured decompression limit by sending a compressed payload with Content-Encoding: br instead of Content-Encoding: gzip, causing unbounded memory allocation and out-of-memory denial of service. The same vulnerability exists in DelegatingDecompressorFrameListener for HTTP/2 connections. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.	Netty
CVE-2026-42586	May 13, 2026	Netty RedisEncoder CRLF Injection before 4.2.13.Final/4.1.133.Final Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, the Netty Redis codec encoder (RedisEncoder) writes user-controlled string content directly to the network output buffer without validating or sanitizing CRLF (\r\n) characters. Since the Redis Serialization Protocol (RESP) uses CRLF as the command/response delimiter, an attacker who can control the content of a Redis message can inject arbitrary Redis commands or forge fake responses. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.	Netty
CVE-2026-42585	May 13, 2026	Netty 4.x Request Smuggling via Malformed Transfer-Encoding (before 4.2.13/4.1.133) Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty incorrectly parses malformed Transfer-Encoding, enabling request smuggling attacks. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.	Netty
CVE-2026-42584	May 13, 2026	Netty HttpClientCodec pairing bug fixed in 4.2.13 & 4.1.133 Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpClientCodec pairs each inbound response with an outbound request by queue.poll() once per response, including for 1xx. If the client pipelines GET then HEAD and the server sends 103, then 200 with GET body, then 200 for HEAD, the queue pairs HEAD with the first 200. The HEAD rule then skips reading that messages body, so the GET entity bytes stay on the stream and the following 200 is parsed from the wrong offset. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.	Netty
CVE-2026-42583	May 13, 2026	Netty Lz4FrameDecoder DoS via Large 32MB Mem Allocation pre-4.2.13 & 4.1.133 Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Lz4FrameDecoder allocates a ByteBuf of size decompressedLength (up to 32 MB per block) before LZ4 runs. A peer only needs a 21-byte header plus compressedLength payload bytes - 22 bytes if compressedLength == 1 - to force that allocation. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.	Netty
CVE-2026-42582	May 13, 2026	Netty QpackDecoder OOB Heap Before 4.2.13.Final Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final, when decoding header blocks, the non-Huffman branch of io.netty.handler.codec.http3.QpackDecoder#decodeHuffmanEncodedLiteral may execute new byte[length] for a string literal before verifying that length bytes are actually present in the compressed field section. The wire encoding allows a very large length to be expressed in few bytes. There is no check that length <= in.readableBytes() before new byte[length]. This vulnerability is fixed in 4.2.13.Final.	Netty