GHSA-jrpc-7vxp-69p6

Suggest an improvement
Source
https://github.com/advisories/GHSA-jrpc-7vxp-69p6
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-jrpc-7vxp-69p6/GHSA-jrpc-7vxp-69p6.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-jrpc-7vxp-69p6
Published
2026-06-19T21:15:59Z
Modified
2026-06-19T21:30:08.829088701Z
Severity
  • 6.3 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N CVSS Calculator
Summary
http4k: `reverseProxy()` defaulted to substring (`Contains`) matching on `Host`; tightened to `Exact`
Details

Impact

reverseProxy() and reverseProxyRouting() matched configured vhosts by substring on the Host header (Contains matcher) by default. The intended use of these functions in http4k is outbound dispatch (e.g. matching AWS service subdomains, per the Contains docstring) and test-time composition of fake backend networks. In either of those contexts the matched Host is set by the calling application, not by an external attacker, so the loose match has no exploit surface.

If, however, reverseProxy() was deployed as a public-facing inbound HTTP handler — which the function technically supports but is not the documented intent — an external attacker could send Host: admin.evil.com and reach a vhost configured as admin, bypassing routing-based authorization.

The Contains matcher's docstring explicitly documented this loose behaviour, but because Contains was the default, callers who never read the matcher docs would still get the loose behaviour.

Who is affected: only deployments using reverseProxy() / reverseProxyRouting() as a public-facing inbound HTTP handler with two or more configured virtual hosts. The intended outbound / test-time usage is unaffected. If you did deploy reverseProxy() inbound and rely on multi-vhost routing for authorization, treat upgrade as urgent.

Patches

| Line | Fixed in | Edition | |------|----------|---------| | v6.x (Community) | 6.49.0.0 | Community | | v5.x (LTS) | 5.42.0.0 | Enterprise — contact enterprise@http4k.org (if reverseProxy() is present in your v5.x line) | | v4.x (LTS) | 4.51.0.0 | Enterprise — contact enterprise@http4k.org (if reverseProxy() is present in your v4.x line) |

The fix changes the default matcher to Exact. Existing callers that genuinely need substring matching (e.g. AWS subdomain dispatch) must explicitly pass matcher = Contains.

Workarounds

For deployments that cannot upgrade immediately: wrap your reverseProxy() with a host-allow-list filter that requires an exact match against expected vhost names before delegating.

Database specific 
{
    "nvd_published_at": null,
    "cwe_ids": [
        "CWE-444"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-19T21:15:59Z",
    "severity": "MODERATE"
}
References

Affected packages

Maven / org.http4k:http4k-core

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
6.0.0.0
Fixed
6.49.0.0

Affected versions

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

Database specific

last_known_affected_version_range 
"< 6.48.0.0"
source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-jrpc-7vxp-69p6/GHSA-jrpc-7vxp-69p6.json"

Maven / org.http4k:http4k-core

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
5.0.0.0
Fixed
5.42.0.0

Affected versions

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

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-jrpc-7vxp-69p6/GHSA-jrpc-7vxp-69p6.json"

Maven / org.http4k:http4k-core

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
4.51.0.0

Affected versions

v6.*
v6.3.0.0
v6.4.1.0
0.*
0.21.0
0.22.0
1.*
1.0.0
1.1.0
1.2.0
1.3.0
1.4.0
1.5.0
1.6.0
1.7.0
1.8.0
1.9.0
1.10.0
1.11.0
1.13.0
1.14.0
1.15.0
1.16.0
1.17.0
1.18.0
1.19.0
1.19.1
1.20.0
1.21.0
1.21.1
1.22.0
1.22.2
1.23.0
1.24.0
1.25.0
1.25.1
1.26.0
1.26.1
1.26.2
1.27.0
1.28.0
1.30.0
1.31.0
1.32.0
1.32.1
1.32.2
1.33.0
1.33.1
2.*
2.0.0
2.0.1
2.0.2
2.0.3
2.0.4
2.0.5
2.1.0
2.1.1
2.1.2
2.2.0
2.2.1
2.3.0
2.4.0
2.5.0
2.5.1
2.6.0
2.7.1
2.8.0
2.8.1
2.9.0
2.10.0
2.10.1
2.11.0
2.11.1
2.11.2
2.11.3
2.12.0
2.13.0
2.14.0
2.15.0
2.16.0
2.16.1
2.17.0
2.17.1
2.17.2
2.18.0
2.18.1
2.18.2
2.18.3
2.18.5
2.19.0
2.20.0
2.21.0
2.21.1
2.21.2
2.22.0
2.23.0
2.23.2
2.23.3
2.23.4
2.24.0
2.25.0
2.25.1
2.25.2
2.25.3
2.25.4
2.26.0
2.26.1
2.26.2
2.26.3
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
3.13.2
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
3.22.3
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
3.27.0
3.28.0
3.29.0
3.30.0
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
3.34.3
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
3.39.4
3.93.4
3.94.0
3.94.1
3.95.0
3.95.1
3.96.0
3.98.0
3.99.0
3.100.0
3.102.0
3.102.1
3.103.0
3.103.1
3.103.2
3.104.0
3.105.0
3.106.0
3.107.0
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
3.136.0
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
3.169.0
3.171.0
3.172.0
3.173.0
3.175.0
3.177.0
3.178.0
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
3.229.0
3.230.0
3.231.0
3.232.0
3.233.0
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
3.244.0
3.245.0
3.245.1
3.246.0
3.247.0
3.248.0
3.250.0
3.251.0
3.252.0
3.253.0
3.254.0
3.255.0
3.256.0
3.256.1
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
4.1.1.0
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

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-jrpc-7vxp-69p6/GHSA-jrpc-7vxp-69p6.json"