CVE-2026-93649: Eclipse Adoptium Eclipse Adoptium website vulnerability
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
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Eclipse Adoptium website (adoptium.net)to a version that resolves this vulnerability.Patch cbb53cf
Event History
Frequently Asked Questions
Which deployments are affected?
Deployments built from commit 0b24ea1 (2025-06-18) through the fix in commit cbb53cf (2026-09-24) are affected. The issue is in the localized post-download route /[locale]/download.
What must an attacker do to exploit this?
An attacker must persuade a victim to follow a crafted adoptium.net download-page URL with a malicious link query parameter. The parameter must begin with an allowed trusted prefix but use dot segments so that browser URL normalization redirects the download to attacker-controlled content.
What is the impact on a victim?
The victim sees the legitimate Eclipse Temurin download confirmation page while the browser downloads a binary selected by the attacker. Exploitation relies on the victim opening the crafted link and potentially trusting or executing the downloaded file.
How can I determine whether a deployment is vulnerable?
Check the deployed source revision or build provenance. A deployment containing commit 0b24ea1 and lacking the fix in commit cbb53cf is affected.