CVE-2026-6322

fast-uri normalize() decoded percent-encoded authority delimiters inside the host component and then re-emitted them as raw delimiters during serialization. A host that combined an allowed domain, an encoded at-sign, and a different domain was re-emitted with the at-sign as a raw userinfo separator, changing the URI's authority to the second domain. Applications that normalize untrusted URLs before host allowlist checks, redirect validation, or outbound request routing can be steered to a different authority than the input appeared to specify. Versions <= 3.1.1 are affected. Update to 3.1.2 or later.

• Published May 5, 2026
• CVSS 7.5 high
• 0.7% chance of exploitation in the next 30 days (EPSS)
• A fix is available

CVE-2026-6322 at the National Vulnerability Database