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

> Unauthenticated attackers can bypass all authentication in AdGuard Home by exploiting an HTTP/2 cleartext upgrade flaw, gaining full administrative access.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Mar 2026
- **Updated:** 12 Mar 2026
- **Also known as:** GHSA-5fg6-wrq4-w5gh, GO-2026-4686

## What is CVE-2026-32136?

CVE-2026-32136 is a critical authentication bypass vulnerability in AdguardTeam AdGuardHome, published on 11 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-32136?

3 open source packages ship an affected version, including github.com/AdguardTeam/AdGuardHome. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/AdguardTeam/AdGuardHome` | Go | All versions | 0.107.73 |
| `github.com/AdguardTeam/AdGuardHome` | Go | All versions | 0.107.73 |
| `github.com/AdguardTeam/AdGuardHome` | Go | All versions | 0.107.73 |

Products: Adguard Adguardhome.

## How do I fix CVE-2026-32136?

Upgrade github.com/AdguardTeam/AdGuardHome to 0.107.73 or later.

## Is CVE-2026-32136 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-32136 exists.

Public exploit code:

- https://github.com/0xdak/CVE-2026-32136_exploit (github_poc): https://github.com/0xdak/CVE-2026-32136_exploit

## Other vulnerabilities in AdguardTeam AdGuardHome

- [CVE-2026-47703](https://insights.sbomify.com/CVE-2026-47703/): AdGuard Home: DoQ-to-UDP State Reduction and Source-Port Oracle (medium 6.3)
- [CVE-2022-32175](https://insights.sbomify.com/CVE-2022-32175/): AdGuardHome - CSRF (medium 5.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-32136 and fix it if it is affected.

What it is: CVE-2026-32136 is a critical authentication bypass vulnerability in AdguardTeam AdGuardHome, published on 11 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-32136 exists.

Affected packages and fixed versions:
- github.com/AdguardTeam/AdGuardHome (Go): affected all versions; fixed in 0.107.73
- github.com/AdguardTeam/AdGuardHome (Go): affected all versions; fixed in 0.107.73
- github.com/AdguardTeam/AdGuardHome (Go): affected all versions; fixed in 0.107.73

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-32136/ (Markdown: https://insights.sbomify.com/CVE-2026-32136/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-32136
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-32136
- OSV: https://osv.dev/vulnerability/CVE-2026-32136

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-32136/
Summaries are generated and may contain mistakes; the official description above is the record.