VULNERABILITY INTELLIGENCE
CVE-2026-86205
CVSS score5.4 MEDIUM
EPSS probability0.27%
CISA KEVNot currently listed
Published2026-09-06
Last modified2026-09-08
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Description
h3 versions before 2.0.1-rc.18 contain an open redirect vulnerability in the redirectBack() utility that fails to sanitize protocol-relative paths in the Referer header pathname. Attackers can craft a same-origin URL with a double-slash path segment that passes origin validation but produces a Location header interpreted by browsers as a protocol-relative redirect to an external domain.
Weakness classification
- disclosure@vulncheck.com: CWE-601