CVE-2026-85676

Description

Dub contains an open redirect vulnerability in the redir_url query parameter that is accepted on every short link without validation or domain allowlist enforcement. Attackers can append the redir_url parameter to any short link to redirect visitors to arbitrary external URLs through the trusted Dub domain, bypassing destination blacklists and potentially enabling phishing attacks with link cloaking enabled.

References

• https://github.com/dubinc/dub
• https://github.com/dubinc/dub/blob/73415cf5e6be13ce9adb7ba5e97474307db34a17/apps/web/lib/middleware/utils/get-final-url.ts
• https://github.com/dubinc/dub/issues/4337
• https://www.vulncheck.com/advisories/dub-open-redirect-via-unrestricted-redir-url-parameter