In the Eclipse Adoptium website (adoptium.net), in every deployment built from commit 0b24ea1…

Why it is Yellow

• CVSS 7.5 high
• Remotely exploitable without logging in

References

• https://github.com/adoptium/adoptium.net/commit/cbb53cf4a41f068a70902217473d7e2fe5d6c6ad
• https://github.com/adoptium/adoptium.net/security/advisories/GHSA-f228-m952-5r6w#event-1046947
• https://gitlab.eclipse.org/security/cve-assignment/-/work_items/313

Original 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