CVE-2026-47703 AdGuard Home: DoQ-to-UDP State Reduction and Source-Port Oracle
AdGuard Home leaks source port information and weakens DNS response matching, potentially allowing attackers to bypass security controls or gather sensitive data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-47703?
CVE-2026-47703 is a medium-severity vulnerability in AdguardTeam AdGuardHome, published on 15 Jul 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 0.107.75, AdGuard Home's client-triggered DoQ forwarding path to a udp:// upstream reduced backend UDP DNS state by producing dns_id=0 or txid=0 and exposed a quoted-port ICMP source-port oracle, weakening DNS response matching for forwarded queries. This issue is fixed in version 0.107.75.
Which versions are affected by CVE-2026-47703?
6 open source packages ship an affected version, including github.com/AdguardTeam/AdGuardHome and github.com/AdguardTeam/dnsproxy. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/AdguardTeam/AdGuardHome Go | All versions | 0.107.75 |
github.com/AdguardTeam/AdGuardHome Go | All versions | 0.107.75 |
github.com/AdguardTeam/AdGuardHome Go | All versions | 0.107.75 |
github.com/AdguardTeam/dnsproxy Go | All versions | 0.81.3 |
github.com/AdguardTeam/dnsproxy Go | All versions | 0.81.3 |
github.com/AdguardTeam/dnsproxy Go | All versions | 0.81.3 |
Products include Adguard Adguardhome.
How do I fix CVE-2026-47703?
Upgrade github.com/AdguardTeam/AdGuardHome to 0.107.75 or later.
Is CVE-2026-47703 being exploited?
There is no known exploitation of CVE-2026-47703 in the wild and no public exploit code.
Other vulnerabilities in AdguardTeam AdGuardHome
Sources
Also known as GHSA-xgx4-4h9w-53pv, GO-2026-5756.