Auth bypass in Adguard Adguardhome
CVE-2026-32136
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.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.008 (56.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 56.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.008 · change: +0.001
Affected products
- Adguard Adguardhome
- Adguardteam Adguardhome — versions < 0.107.73
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/AdguardTeam/AdGuardHome/security/advisories/GHSA-5fg6-wrq4-w5gh (Exploit, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-32136?
- CVE-2026-32136 is a critical-severity vulnerability in Adguard Adguardhome, classified under Improper Authentication. CVSS score: 9.8/10. Published 2026-03-11.
- How severe is CVE-2026-32136?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2026-32136 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.