io.vertx/vertx-web: Eclipse Vert.x Web Client: Information disclosure via improper cookie domain validation

A flaw was found in Eclipse Vert.x Web Client. The WebClientSession component does not properly validate the Domain attribute of a Set-Cookie response header against the originating server's domain. This vulnerability allows a remote attacker to inject a cookie scoped to an arbitrary third-party...

CVE-2026-15076: Origin Validation Error

In versions up to and including 4.5.29 4.x branch and 5.1.4 5.x branch, the WebClientSession component of Eclipse Vert.x Web Client does not validate that the Domain attribute of a Set-Cookie response header matches the originating server's domain, in violation of RFC 6265 section 5.3. An attacke...