CVE-2025-11966: Vert.x-Web vulnerable to Stored Cross-site Scripting in directory listings via file names

CVE-2025-11966 · Severity: medium · CVSS 6.4 · Published 2025-10-22

In Eclipse Vert.x versions [4.0.0, 4.5.21] and [5.0.0, 5.0.4], when "directory listing" is enabled, file and directory names are inserted into generated HTML without proper escaping in the href, title, and link attributes. An attacker who can create or rename files or directories within a served path can craft filenames containing malicious script or HTML content, leading to stored cross-site scripting (XSS) that executes in the context of users viewing the affected directory listing.

Technologies: io.vertx:vertx-web (Maven). Vendors: Maven.

Quick answers

Is CVE-2025-11966 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2025-11966 being exploited in the wild.
How severe is CVE-2025-11966?
Medium severity, with a CVSS score of 6.4, published 22 October 2025.
Which products and versions are affected?
io.vertx:vertx-web (Maven) ECOSYSTEM:introduced=0,fixed=4.5.22.
Is there a fix for CVE-2025-11966?
Yes. io.vertx:vertx-web (Maven): upgrade to 4.5.22 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2025-11966?
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 4.5.22 or later
    # set io.vertx:vertx-web to 4.5.22 in your pom.xml or build.gradle

Affected products

  • io.vertx:vertx-web (Maven) ECOSYSTEM:introduced=0,fixed=4.5.22

Identifiers

  • CVE-2025-11966
  • GHSA-45p5-v273-3qqr

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