# CVE-2018-12542: Eclipse Vert.x does not properly neutralize '' (forward slashes) sequences that can resolve to an external location

Source: https://junglewise.ai/threats/cve-2018-12542-eclipse-vert-x-does-not-properly-neutralize-forward-slashes  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2018-10-17  
License: CC BY 4.0 with a link back

CVE-2018-12542 · Severity: low · CVSS 3 · Published 2018-10-17

Eclipse Vert.x does not properly neutralize '' (forward slashes) sequences that can resolve to an external location

Technologies: [io.vertx:vertx-web (Maven)](https://junglewise.ai/threats/technologies/io-vertx-vertx-web). Vendors: [Maven](https://junglewise.ai/threats/vendors/maven).

## Quick answers

**Is CVE-2018-12542 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2018-12542 being exploited in the wild.

**How severe is CVE-2018-12542?** Low severity, with a CVSS score of 3, published 17 October 2018.

**Which products and versions are affected?** io.vertx:vertx-web (Maven) ECOSYSTEM:introduced=3.0.0,fixed=3.5.4.

**Is there a fix for CVE-2018-12542?** Yes. io.vertx:vertx-web (Maven): upgrade to 3.5.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2018-12542?** Check whether you run io.vertx:vertx-web (Maven) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- io.vertx:vertx-web (Maven): upgrade to 3.5.4 or later

  ```sh
  # set io.vertx:vertx-web to 3.5.4 in your pom.xml or build.gradle
  ```


## Affected products

- io.vertx:vertx-web (Maven) ECOSYSTEM:introduced=3.0.0,fixed=3.5.4

## Identifiers

- CVE-2018-12542
- GHSA-h39x-m55c-v55h

## Related threats

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- [Vert.x-Web Access Control Flaw in StaticHandler’s Hidden File Protection for Files Under Hidden Directories](https://junglewise.ai/threats/cve-2025-11965-vert-x-web-access-control-flaw-in-statichandler-s-hidden-file)
- [StaticHandler disclosure of classpath resources on Windows when mounted on a wildcard route](https://junglewise.ai/threats/cve-2023-24815-statichandler-disclosure-of-classpath-resources-on-windows-when)
- [Path Traversal in Eclipse Vert](https://junglewise.ai/threats/cve-2019-17640-path-traversal-in-eclipse-vert)
- [Cross-Site Request Forgery in Vert.x-Web framework](https://junglewise.ai/threats/cve-2020-35217-cross-site-request-forgery-in-vert-x-web-framework)