{"id":"CVE-2026-32136","aliases":["GHSA-5fg6-wrq4-w5gh","GO-2026-4686"],"url":"https://o3.security/vulnerability/CVE-2026-32136","summary":"AdGuard Home: HTTP/2 Cleartext (h2c) Upgrade Authentication Bypass","details":"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.","published":"2026-03-11T21:42:31.422Z","modified":"2026-08-12T03:51:36.561238113Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/AdguardTeam/AdGuardHome","fixedVersion":"0.107.73"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/AdguardTeam/AdGuardHome/security/advisories/GHSA-5fg6-wrq4-w5gh"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/32xxx/CVE-2026-32136.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-32136"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:36.561238113Z"}}