CVE-2023-39685 is a high-severity (CVSS 7.5) Code Injection vulnerability in org.hjson:hjson. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for org.hjson:hjson — see the affected versions and patch details below.
hson-java vulnerable to denial of service
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.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-39685.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
org.hjson:hjsonReal-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
An issue in hjson-java up to v3.0.0 allows attackers to cause a Denial of Service (DoS) via supplying a crafted JSON string to string a StringIndexOutOfBoundsException.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.hjson:hjson | all versions | 3.0.1org.hjson:hjson:3.0.1 |
Affected Products
hjsonhjsonResearch 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 org.hjson:hjson, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.hjson:hjson to 3.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-39685 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
Frequently Asked Questions
Is CVE-2023-39685 in your dependencies?
Find it across Maven, including transitive dependencies.