Description
The hickory-dns recursor in hickory-recursor 0.25.0-alpha.3 through 0.25.2 and hickory-resolver 0.26.0-alpha.1 before 0.26.2 iterates every out-of-bailiwick NS target lacking glue in a referral without any per-query work budget. Remote attackers can serve such referrals to force A and AAAA lookups per target, amplifying traffic against remote servers or exhausting recursor resources.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| hickory-dns | hickory-dns | 0.25.0-alpha.3 – ≤ 0.25.2, 0.26.0-alpha.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-resolver | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | rust-hickory-resolver | No fix yet | — |
| Ubuntu 26.04 LTS | rust-hickory-resolver | No fix yet | — |
| Ubuntu 24.04 LTS | rust-hickory-resolver | No fix yet | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| crates.io | hickory-recursor | >= 0.25.0-alpha.3 | — | RUSTSEC-2026-0521 |
| crates.io | hickory-resolver | >= 0.26.0-beta.1, < 0.26.2 | 0.26.2 | RUSTSEC-2026-0515 |
References
- GitHub Security Advisory (GHSA-6h5c-jjg5-wj59) vendor-advisory
- VulnCheck Advisory: Hickory-DNS Recursor 0.25.0-alpha.3 through 0.25.2 Glueless-NS Referral Amplification third-party-advisory