GitHub Advisoryadvisory · Maven

GHSA-57rv-r2g8-2cj3 Netty has HttpClientCodec response desynchronization

HIGH Published 2026-05-07 Modified 2026-05-14 Official page ↗
Aliases
CVE-2026-42584
Ecosystem
Maven
Packages
io.netty:netty-codec-http
Severity
High
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Weaknesses
CWE-444
Reviewed
2026-05-07

Affected packages

• Maven io.netty:netty-codec-http: >= 4.2.0.Alpha1, < 4.2.13.Final → fixed in 4.2.13.Final • Maven io.netty:netty-codec-http: < 4.1.133.Final → fixed in 4.1.133.Final

Description

Summary If HttpClientCodec is configured, there are use cases when a response body from one request, can be parsed as another's. Details 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 message’s body, so the GET entity bytes stay on the stream and the following 200 is parsed from the wrong offset. Prerequisites • HTTP/1.1 pipelining • HEAD in the pipeline • The server sends 1xx PoC ```java @Test public void test() { EmbeddedChannel channel = new EmbeddedChannel(new HttpClientCodec()); assertTrue(channel.writeOutbound(new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, "/1"))); ByteBuf request = channel.readOutbound(); request.release(); assertNull(channel.readOutbound()); assertTrue(channel.writeOutbound(new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.HEAD, "/2"))); request = channel.readOutbound(); request.release(); assertNull(channel.readOutbound()); String responseStr = "HTTP/1.1 103 Early Hints\r\n\r\n" + "HTTP/1.1 200 OK\r\nContent-Length: 5\r\n\r\nhello" + "HTTP/1.1 200 OK\r\n\r\n"; assertTrue(channel.writeInbound(Unpooled.copiedBuffer(responseStr, CharsetUtil.US_ASCII))); // Response 1 HttpResponse response = channel.readInbound(); assertEquals(HttpResponseStatus.EARLY_HINTS, response.status()); LastHttpContent last = channel.readInbound(); assertEquals(0, last.content().readableBytes()); last.release(); // Response 2 response = channel.readInbound(); assertEquals(HttpResponseStatus.OK, response.status()); last = channel.readInbound(); assertEquals(0, last.content().readableBytes()); last.release(); // Response 3 FullHttpResponse response1 = channel.readInbound(); assertTrue(response1.decoderResult().isFailure()); assertEquals(0, response1.content().readableBytes()); response1.release(); assertFalse(channel.finish()); } ``` Impact Integrity/availability of HTTP parsing on that connection, unsafe reuse of the socket.

Related

Alias · CVE (1)

  • CVE-2026-42584 Netty is an asynchronous, event-driven network application framework. vulnerability

Weakness · CWE (1)

  • CWE-444 Inconsistent Interpretation of HTTP Requests weakness

References