When incoming DNS over HTTPS support is enabled using the nghttp2 provider, and queries are routed to a tcp-only or DNS over TLS backend, an attacker can trigger an assertion failure in DNSdist by sending a request for a zone transfer (AXFR or IXFR) over DNS over HTTPS, causing the process to stop and thus leading to a Denial of Service. DNS over HTTPS is not enabled by default, and backends are using plain DNS (Do53) by default.
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alpine Linux | — | Upgrade dnsdist | Aug 22, 2024 | May 13, 2024 |
| Debian | — | Upgrade dnsdist | Jul 27, 2026 | Jul 27, 2026 |
| Freebsd | — | Upgrade dnsdist | May 15, 2024 | May 13, 2024 |
| Suse | — | Upgrade dnsdist | Dec 5, 2025 | Dec 5, 2025 |
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