GHSA-cp4w-6x4w-v2h5 is a medium-severity (CVSS 6.5) CWE-706 vulnerability in lambdaisland:uri. 1 public exploit reference exists, so weaponization risk is real. A fix is available for lambdaisland:uri — see the affected versions and patch details below.
lambdaisland/uri `authority-regex` returns the wrong authority
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-cp4w-6x4w-v2h5.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-cp4w-6x4w-v2h5 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
lambdaisland:uriReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Summary
authority-regex allows an attacker to send malicious URLs to be parsed by the lambdaisland/uri and return the wrong authority. This issue is similar to CVE-2020-8910.
Details
This regex doesn't handle the backslash (\) character in the username correctly, leading to a wrong output.
Payload: https://example.com\\@google.com
The returned host is google.com, but the correct host should be example.com.
urllib3 (Python) and google-closure-library (Javascript) return example.com as the host. Here the correct (or current) regex used by google-closure-library:
PoC
(ns poc.core)
(require '[lambdaisland.uri :refer (uri)])
(def myurl "https://example.com\\@google.com")
(defn -main
[]
(println myurl)
(println (:host (uri myurl)))
)
Impact
The library returns the wrong authority, and it can be abused to bypass host restrictions.
Reference
WHATWG Living URL spec, section 4.4 URL Parsing, host state: https://url.spec.whatwg.org/#url-parsing
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | lambdaisland:uri | all versions | 1.14.120lambdaisland:uri:1.14.120 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for lambdaisland:uri, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update lambdaisland:uri to 1.14.120 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-cp4w-6x4w-v2h5 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-cp4w-6x4w-v2h5 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-cp4w-6x4w-v2h5. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Frequently Asked Questions
Is GHSA-cp4w-6x4w-v2h5 in your dependencies?
O3 Security finds GHSA-cp4w-6x4w-v2h5 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.