CVE-2026-93649

Published Oct 15, 2026 Modified Oct 15, 2026 CWE-494 CWE-601

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

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Weakness Type (CWE)

CWE-494 CWE-494
CWE-601 CWE-601

References

Frequently Asked Questions

What is CVE-2026-93649? +
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
How do I check if I'm vulnerable to CVE-2026-93649? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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