CVE-2026-93649 Open redirect in Adoptium Temurin
Attackers can trick users into downloading malicious binaries by bypassing URL validation on the Eclipse Adoptium download page via path traversal in query parameters.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-93649?
CVE-2026-93649 is a high-severity vulnerability in Eclipse Foundation Adoptium Temurin, published on 15 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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
Which versions are affected by CVE-2026-93649?
How do I fix CVE-2026-93649?
No fix has been published for CVE-2026-93649 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-93649 being exploited?
There is no known exploitation of CVE-2026-93649 in the wild and no public exploit code.
Sources
Also known as GHSA-5w25-6xp6-x3fm, GHSA-f228-m952-5r6w.