CVE-2026-32136 — AdGuard Home: HTTP/2 Cleartext (h2c) Upgrade Authentication Bypass
AdGuard Home is a network-wide software for blocking ads and tracking. Prior to 0.107.73, an unauthenticated remote attacker can bypass all authentication in AdGuardHome by send…
Published: 2026-03-11 · CVSS: 9.8 · CVSS 3.1
AdGuard Home is a network-wide software for blocking ads and tracking. Prior to 0.107.73, an unauthenticated remote attacker can bypass all authentication in AdGuardHome by sending an HTTP/1.1 request that requests an upgrade to HTTP/2 cleartext (h2c). Once the upgrade is accepted, the resulting HTTP/2 connection is handled by the inner mux, which has no authentication middleware attached. All subsequent HTTP/2 requests on that connection are processed as fully authenticated, regardless of whether any credentials were provided. This vulnerability is fixed in 0.107.73.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7