CVE-2018-12544 is a critical-severity (CVSS 9.8) XML External Entity (XXE) vulnerability in io.vertx:vertx-core. A fix is available for io.vertx:vertx-core — see the affected versions and patch details below.
Moderate severity vulnerability that affects io.vertx:vertx-core
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
io.vertx:vertx-coreReal-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
In version from 3.5.Beta1 to 3.5.3 of Eclipse Vert.x, the OpenAPI XML type validator creates XML parsers without taking appropriate defense against XML attacks. This mechanism is exclusively when the developer uses the Eclipse Vert.x OpenAPI XML type validator to validate a provided schema.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.vertx:vertx-core | ≥ 3.5.0&&< 3.5.4 | 3.5.4io.vertx:vertx-core:3.5.4 |
Affected Products
vert.xeclipseDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.vertx:vertx-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update io.vertx:vertx-core to 3.5.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-12544 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.
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.
| Product | Fixed in | Advisory |
|---|---|---|
| Text-Only RHOAR | vertx-web | RHSA-2018:2946 |
Frequently Asked Questions
Is CVE-2018-12544 in your dependencies?
Find it across Maven, including transitive dependencies.