CVE-2018-6591 — converse.js
MEDIUMCVE-2018-6591 is a medium-severity (CVSS 5.3) Information Exposure vulnerability in converse.js. A fix is available for converse.js — see the affected versions and patch details below.
Converse.js Exposure of Sensitive Information
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
CVE-2018-6591 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 377,333 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
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
converse.jsnpmDescription
Converse.js and Inverse.js through 3.3 allow remote attackers to obtain sensitive information because it is too difficult to determine whether safe publication of private data was configured or even intended. For example, users might have an expectation that chatroom bookmarks are private, but the various interacting software components do not necessarily make that happen.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | converse.js | all versions | 3.3.3npm install converse.js@3.3.3 |
| 🐘Packagist | jcbrand/converse.js | all versions | 3.3.3composer require jcbrand/converse.js:^3.3.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for converse.js, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update converse.js to 3.3.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-6591 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 CVE-2018-6591 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2018-6591. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2018-6591 in your dependencies?
O3 Security finds CVE-2018-6591 across npm, Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.