Netty vulnerabilities, page 5
111 vulnerabilities
Known vulnerabilities in Netty products, newest first, with CVSS severity, EPSS, KEV listings and ransomware use, across 4 products.
CVE-2026-100660ubuntunetty+1
EPSS score0.38%
Netty's HTTP/3 codec (io.netty:netty-codec-http3) from 4.2.0.Final through 4.2.17.Final retains unbounded per-stream QPACK encoder state. QpackEncoder stores a queue and a dynamic-table index tracker for every encoded field section that references the QPACK dynamic table, keyed by the peer-controlled QUIC stream ID, and these entries are released only when the remote decoder sends a Section Acknowledgment or Stream Cancellation instruction — not when the HTTP/3 stream completes. There is no limit on the number of tracked streams, field sections, or retained bytes. A remote, unauthenticated HTTP/3 client can advertise a non-zero QPACK dynamic-table capacity, acknowledge the table insertion so the server reuses a dynamically indexed response header, and then omit all mandatory Section Acknowledgments while issuing sequential requests over a single QUIC connection, bypassing concurrent-stream limits and causing unbounded heap growth until the server exhausts memory (denial of service). Fixed in 4.2.18.Final.CVE-2026-100664ubuntunetty+1EPSS score0.33%
Netty's HTTP/3 codec (io.netty:netty-codec-http3) versions 4.2.2.Final through 4.2.17.Final builds the HTTP/3 :authority pseudo-header from the HTTP/1 Host header before considering the authority of an absolute-form HTTP/1 request-target. In HttpConversionUtil.toHttp3Headers(HttpMessage, boolean) — reached via Http3FrameToHttpObjectCodec(false) — a non-empty Host header takes precedence over the request-target authority, contrary to the HTTP/1.1 rule that a server receiving an absolute-form request-target must ignore the Host header. In a Netty-based HTTP/1-to-HTTP/3 gateway, proxy, or protocol bridge, a remote client can send a request such as "GET https://trusted.example/admin HTTP/1.1" with "Host: attacker.example", causing components that validate, authorize, or route on the RFC-defined request-target authority to reach a different decision than the upstream HTTP/3 peer, which receives :authority derived from the conflicting Host header. This authority confusion can affect virtual-host routing, allow-list checks, backend selection, cache keys, and URL generation. The advisory reports integrity impact only (no code execution, memory corruption, or availability impact). Fixed in 4.2.18.Final.CVE-2026-100666debiannetty+2EPSS score0.24%
Netty's HttpServerCodec (io.netty:netty-codec-http) in versions 4.2.0.Final through 4.2.16.Final and in versions up to and including 4.1.136.Final pairs each outbound response with an inbound request by calling pollMethod() once per response, including for 1xx informational responses. If a client pipelines an HTTP/1.1 GET carrying an Expect: 100-continue header followed by a HEAD request, the 100 Continue response consumes the queued GET method, so the subsequent 200 OK for the GET is paired with HEAD and its body is dropped, while the following 200 OK for the HEAD request is written with a body. This desynchronizes HTTP parsing on the connection: the GET entity is never delivered and the HEAD response body is interpreted as the GET body, resulting in response splitting and unsafe connection reuse. Fixed in 4.2.17.Final and 4.1.137.Final.CVE-2026-100659ubuntunetty+1EPSS score0.24%
Netty's HTTP/3 codec (io.netty:netty-codec-http3) in versions 4.2.0.Final through 4.2.17.Final does not enforce the RFC 9114 requirement that the :authority pseudo-header field and a literal host header field, when both present, carry the same value. A remote unauthenticated peer can send a single HEADERS frame containing both fields with differing, attacker-controlled values; the request is accepted and delivered to the application with two conflicting authorities, allowing routing, virtual-host, and access-control decisions to be bypassed when different components in the request path consult different fields. This issue is fixed in 4.2.18.Final.CVE-2026-100662ubuntunetty+1EPSS score0.34%
Netty's HTTP/3 codec (io.netty:netty-codec-http3) versions 4.2.0.Final through 4.2.17.Final contain an uncontrolled resource consumption vulnerability in the QPACK encoder-stream instruction decoder (QpackEncoderHandler, installed on the peer-initiated unidirectional QPACK encoder stream, type 0x02). The handler accepts an attacker-declared string-literal length of up to Integer.MAX_VALUE (~2 GiB) for the Name Length and Value Length fields of the "Insert With Literal Name" instruction (RFC 9204 §4.3.3), with no per-instruction or per-literal length cap and no cumulation-size limit; the existing HTTP/3 limits (maxHeaderListSize, maxUnknownFramePayloadLength, DEFAULT_MAX_FIELD_SECTION_SIZE) are not applied to this handler. A remote, unauthenticated peer with an established HTTP/3 connection to a default Netty HTTP/3 server can declare a very large literal length and then trickle fewer bytes than declared, causing the ByteToMessageDecoder MERGE cumulator to retain and grow the per-connection buffer, and ultimately triggering a large byte-array allocation. This leads to unbounded per-connection heap growth and OutOfMemoryError, resulting in denial of service. Fixed in 4.2.18.Final.CVE-2026-100663ubuntunetty+1EPSS score0.30%
Netty's HTTP/3 codec (io.netty:netty-codec-http3) from 4.2.2.Final through 4.2.17.Final does not special-case HTTP/1 CONNECT authority-form request-targets when converting HTTP/1 messages to HTTP/3 in HttpConversionUtil.toHttp3Headers. The authority-form target (e.g., "CONNECT trusted.example:443") is parsed as a URI, so its host is emitted as :scheme, :path is set to "/", and the HTTP/1 Host header is used as :authority; if no Host header is present the CONNECT target is dropped. In a Netty-based HTTP/1-to-HTTP/3 proxy or gateway, a remote client can send a CONNECT request whose Host header names a different authority than the request-target, producing a malformed HTTP/3 CONNECT whose tunnel :authority is attacker-controlled. This can bypass tunnel allow-lists, egress policy, backend selection, or audit controls that validate the HTTP/1 CONNECT request-target before forwarding over HTTP/3. The issue is fixed in 4.2.18.Final.CVE-2026-100665ubuntunetty+1EPSS score0.29%
Netty versions from 4.2.11.Final before 4.2.18.Final contain an incomplete hostname verification fix in the QUIC certificate verification path when using a plain X509TrustManager. The BoringSSLCertificateVerifyCallback discards the SSLEngine for plain trust managers, preventing endpoint identification from running even when HTTPS verification is configured. Attackers on the network path can present a certificate chain for the wrong hostname that the plain trust manager accepts, bypassing hostname authentication for QUIC clients.CVE-2026-100661ubuntunetty+1EPSS score0.34%
Netty's HTTP/3 codec (io.netty:netty-codec-http3) versions 4.2.0.Final through 4.2.17.Final contain a denial-of-service vulnerability in the QPACK prefixed-integer decoder (QpackUtil.decodePrefixedInteger), which does not bound the number of continuation bytes it will process. A remote, unauthenticated peer can open a QPACK unidirectional stream (type 0x02 encoder or 0x03 decoder) and send a first byte with all prefix bits set (e.g. 0xFF for a 7-bit prefix or 0x3F for a 5-bit prefix) followed by an endless run of 0x80 continuation bytes. The decoder returns -1 ('need more bytes'), so callers never consume the input, the ByteToMessageDecoder cumulator grows without bound, and each decode() invocation re-scans the whole accumulated buffer, yielding O(N^2) CPU cost. The result is unbounded per-connection heap growth (OutOfMemoryError) and event-loop CPU starvation, reachable in every configuration. Fixed in 4.2.18.Final.CVE-2026-44894chainguardapache-hop+56EPSS score0.19%
Netty is a network application framework for development of protocol servers and clients. NoQuicTokenHandler is the tokenHandler used when the application does not set one. Prior to version 4.2.15.Final, its writeToken() returns false (server will not send Retry — acceptable), but validateToken() unconditionally `return 0`. In QuicheQuicServerCodec.handlePacket(), a non-negative return from validateToken() is interpreted as 'token is valid, ODCID starts at offset 0', causing the server to call quiche_accept as if the client's address had been validated by a Retry round-trip. Per RFC 9000 §8.1, a validated address lifts the 3× anti-amplification send limit. Thus any attacker who includes ANY non-empty token bytes in an Initial packet — with a spoofed victim source IP — causes the Netty server to treat the victim as validated and reflect full-size handshake flights (certificates, etc.) toward it without the 3× cap. The correct 'no token handler' semantics would be to return -1 (invalid) so the normal un-validated path and amplification limit apply. Version 4.2.15.Final patches the issue.CVE-2026-44249chainguardairbyte-server+367EPSS score1.29%
Netty is a network application framework for development of protocol servers and clients. In netty-handler prior to versions 4.1.135.Final and 4.2.15.Final, an attacker can bypass IPv6 subnet rules due to an incorrect masking operation in IpSubnetFilterRule.compareTo(). Valid public IP addresses can bypass the restrictions. Versions 4.1.135.Final and 4.2.15.Final patch the issue.CVE-2026-44893chainguardapache-activemq-artemis+121EPSS score0.88%
Netty is a network application framework for development of protocol servers and clients. In netty-codec-haproxy prior to versions 4.1.135.Final and 4.2.15.Final, when decoding a PP2_TYPE_SSL TLV, HAProxyMessage.readNextTLV() first calls `header.retainedSlice(header.readerIndex(), length)` and only then reads the 1-byte client field and 4-byte verify field. If the attacker sets the TLV length below 5, the subsequent readByte/readInt throws IndexOutOfBoundsException. HAProxyMessageDecoder only catches HAProxyProtocolException around this call, so the IOOBE propagates and the retained slice on the pooled cumulation buffer is never released. Versions 4.1.135.Final and 4.2.15.Final patch the issue.CVE-2026-44891chainguardapache-hop+48EPSS score0.73%
Netty is a network application framework for development of protocol servers and clients. Prior to 4.1.136.Final and 4.2.16.Final, io.netty.handler.codec.stomp.StompSubframeDecoder fails to limit the total number of headers or their cumulative size per frame, and the maxLineLength parameter only restricts individual header lines. An attacker can send a large number of short headers that are accumulated in memory inside DefaultStompHeadersSubframe until the JVM throws an OutOfMemoryError, causing denial of service for servers exposing a STOMP endpoint based on StompSubframeDecoder. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.CVE-2026-44892chainguardapache-hop+54EPSS score0.49%
Netty is a network application framework for development of protocol servers and clients. Prior to version 4.2.15.Final, the default configuration of the `Http3ConnectionHandler` in the Netty HTTP/3 codec lacks an enforced maximum header size limit. When a peer does not explicitly specify `HTTP3_SETTINGS_MAX_FIELD_SECTION_SIZE`, the implementation defaults to an unbounded limit. This insecure default configuration allows a malicious client or server to send an enormous number of headers, leading to a memory exhaustion Denial of Service via an `OutOfMemoryError`. Version 4.2.15.Final contains a patch.CVE-2026-44890chainguardapache-hop+52EPSS score0.85%
Netty is a network application framework for development of protocol servers and clients. In netty-codec-redis prior to versions 4.1.135.Final and 4.2.15.Final, an attacker can cause DoS by sending crafted Redis payloads across multiple connections without `\r\n`. This exhausts the server's direct memory pool (OutOfDirectMemoryError), preventing legitimate connections from being processed. Versions 4.1.135.Final and 4.2.15.Final patch the issue.CVE-2026-44248chainguardapache-activemq-artemis+48EPSS score0.72%
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.CVE-2026-44250chainguardapache-hop+52EPSS score0.85%
Netty is a network application framework for development of protocol servers and clients. In netty-codec-redis prior to versions 4.1.135.Final and 4.2.15.Final, an attacker can cause DoS by sending a crafted Redis payload with deeply nested arrays. This forces the server to allocate a massive number of state objects and collections, leading to memory exhaustion and an OutOfMemoryError. Versions 4.1.135.Final and 4.2.15.Final patch the issue.CVE-2026-75596chainguardakhq+176EPSS score0.37%
Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Final and 4.2.17.Final, the default io.netty.handler.ssl.SniHandler constructors use the pre-handshake ClientHello aggregation path in handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java at io.netty.handler.ssl.SslClientHelloHandler#decode, where handshakeBuffer.clear() and writeBytes() recopy all previously received body bytes for every additional TLS record. An unauthenticated remote peer can advertise a large ClientHello and deliver its body in thousands of tiny records, causing quadratic CPU work on the event loop before the TLS handshake completes and degrading TLS handling for other clients. This issue is fixed in versions 4.1.137.Final and 4.2.17.Final.CVE-2026-75595chainguardakhq+180EPSS score0.28%
Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Fina and 4.2.17.Final, io.netty.handler.ssl.SslClientHelloHandler#decode checks the wrong offset before reading the four-byte TLS handshake header, so a ClientHello whose handshake header spans records can cause an IndexOutOfBoundsException and invoke select(ctx, null). This selects the default SslContext instead of the SNI-specific context. In deployments where per-SNI clientAuth=REQUIRE is the sole mutual TLS gate, the default SslContext uses clientAuth=NONE or clientAuth=OPTIONAL, and no application-layer certificate verification exists, an unauthenticated remote attacker can bypass the protected route's mutual TLS requirement. This issue is fixed in versions 4.1.137.Final and 4.2.17.Final.CVE-2026-45674chainguardairbyte-server+240EPSS score0.29%
Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty's DnsResolveContext fails to validate the origin (bailiwick) of CNAME records in DNS responses. Versions 4.1.135.Final and 4.2.15.Final patch the issue.CVE-2026-45536chainguardairbyte-server+225EPSS score0.19%
Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, netty_unix_socket_recvFd sets msg_control to `char control[CMSG_SPACE(sizeof(int))]` (line 940) — 24 bytes on 64-bit Linux. A peer-sent SCM_RIGHTS cmsg carrying two ints has cmsg_len = CMSG_LEN(8) = 24, which fits exactly with no MSG_CTRUNC, so the kernel installs both fds in the receiving process. The subsequent check `cmsg->cmsg_len == CMSG_LEN(sizeof(int))` (line 972, expected 20) fails, the branch that would read the fd is skipped, and neither installed fd is closed. The for(;;) loop calls recvmsg again (non-blocking → EAGAIN → Java maps to 0 → read loop exits normally), leaving two leaked fds per message. There is no MSG_CTRUNC handling. Reachable via Epoll/KQueue DomainSocketChannel when the application opts into DomainSocketReadMode.FILE_DESCRIPTORS (non-default). Versions 4.1.135.Final and 4.2.15.Final patch the issue.