CVE-2026-86205 — h3 before 2.0.1-rc.18 Open Redirect via redirectBack()
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…
Published: 2026-09-06 · CVSS: 5.3 · CVSS 4.0
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7