CVE-2026-32136 — AdGuard Home: HTTP/2 Cleartext (h2c) Upgrade Authentication Bypass

Description (CNA)

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.

Affected (CNA)

Vendor / product	Versions
AdguardTeam / AdGuardHome	affected < 0.107.73

CWE

CWE-287

References

https://github.com/AdguardTeam/AdGuardHome/security/advisories/GHSA-5fg6-wrq4-w5gh

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.