CVE-2026-93649

/// Technical description

In the Eclipse Adoptium website (adoptium.net), in every deployment built from commit 0b24ea1 (2025-06-18) up to the fix in commit cbb53cf (2026-09-24), the post-download page /[locale]/download takes a download URL from the "link" query parameter and automatically navigates to it with a meta http-equiv="refresh". The URL is checked against a list of trusted prefixes using String.startsWith() on the raw string, while the browser applies RFC 3986 dot-segment normalisation before navigating, so a value such as https://github.com/adoptium/temurin/../../attacker/malware/releases/download/v1/jdk.exe passes the check but resolves to an attacker-controlled repository. A victim who follows a crafted adoptium.net link is shown the genuine "Thank you for downloading Eclipse Temurin" page while their browser downloads a binary of the attacker's choosing

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References