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AdguardhomeApplication · Adguard

CVE-2026-32136

CRITICAL · 9.8 CVSS v3.1 Published 2026-03-11
Fix available
A fix is available. Upgrade to 0.107.73 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

AdGuard Home versions before 0.107.73 contain an authentication bypass where an unauthenticated attacker sends an HTTP/1.1 request requesting HTTP/2 cleartext (h2c) upgrade. When the server accepts this upgrade, the resulting HTTP/2 connection is handled by an inner multiplexer that lacks authentication middleware, causing all subsequent HTTP/2 requests on that connection to be processed as fully authenticated regardless of credentials provided.

MitigationUpgrade AdGuard Home to version 0.107.73 or later. If immediate patching is not possible, consider restricting external access to the admin interface at the network level.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
AdguardhomeApplication
Affected:< 0.107.73

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed AdGuard Home version
    Run 'AdGuardHome --version' or check the version displayed in the admin web interface under 'Settings > About'. Compare the version number to 0.107.73.
    Affected if The installed version is below 0.107.73 (e.g., 0.107.72, 0.107.71, etc.).
  2. Identify admin interface binding
    Examine AdGuard Home configuration file (usually adguardhome.yaml) for the 'bind_hosts' setting under the 'http' section of the 'admin' configuration. Also check if TLS is enabled on the admin interface.
    Affected if The admin interface binds to 0.0.0.0 or an externally reachable IP address without TLS, making it accessible to unauthenticated network attackers.
  3. Verify HTTP/2 cleartext (h2c) upgrade capability
    Send an HTTP/1.1 request to the admin interface with 'Connection: Upgrade' and 'Upgrade: h2c' headers. Check if the server responds with 'HTTP/1.1 101 Switching Protocols' accepting the upgrade.
    Affected if The server accepts the h2c upgrade and switches to HTTP/2 without requiring authentication on the new connection.
  4. Confirm HTTP/2 requests bypass authentication
    After obtaining the h2c upgrade, send an HTTP/2 request to an authenticated endpoint (e.g., /control/status) without providing any credentials. Observe if the request succeeds as if fully authenticated.
    Affected if HTTP/2 requests on the upgraded connection are processed without authentication checks, returning authenticated data without credentials.

You are affected if AdGuard Home version is below 0.107.73 AND the admin interface is network-accessible to untrusted parties, allowing them to trigger the h2c upgrade bypass.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 0.107.73 or later
Fixed in 0.107.73
Interim mitigation

Upgrade AdGuard Home to version 0.107.73 or later. If immediate patching is not possible, consider restricting external access to the admin interface at the network level.

Recommended fix High confidence

0.107.73

  1. 1. Back up your current AdGuard Home configuration (usually in /etc/adguardhome.yaml or the data directory)
  2. 2. Stop the AdGuard Home service
  3. 3. Update AdGuard Home to version 0.107.73 or later using your package manager or by downloading from the official releases
  4. 4. Verify the installed version matches or exceeds 0.107.73
  5. 5. Start the AdGuard Home service
  6. 6. Confirm authentication is working correctly by accessing the admin interface with valid credentials

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Adguardhome Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,840
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,544.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-32136 in production — separate from our analysis above.

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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