Description
The Hickory DNS recursor in all versions of hickory-recursor and in hickory-resolver 0.26.0-beta.1 before 0.26.2 (recursor feature) is vulnerable to ghost domain names attacks because it reuses child-side apex NS RRsets cached from zone NS queries for iterative resolution. By repeatedly querying a zone's NS records, an attacker keeps the stale RRset cached indefinitely, letting name servers whose delegation the parent revoked keep answering for the zone.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| hickory-dns | hickory-dns | ≤ 0.26.0-alpha.1, 0.26.0-beta.1 – < 0.26.2 | 0.26.2 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | rust-hickory-resolver | 0.26.3-1 | — |
| Debian 13 | rust-hickory-recursor +1 | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | rust-hickory-recursor +1 | No fix yet | — |
| Ubuntu 26.04 LTS | rust-hickory-recursor +1 | No fix yet | — |
| Ubuntu 24.04 LTS | rust-hickory-resolver | No fix yet | — |
References
- GitHub Security Advisory (GHSA-2hxp-x833-73f7) vendor-advisory
- VulnCheck Advisory: Hickory DNS Recursor Ghost Domain Attack via Child-Side NS RRset Caching third-party-advisory