Description
The hickory-resolver component of Hickory DNS 0.25.0 before 0.26.2 follows irrelevant CNAME records when resolving recursive queries, sending queries that are unnecessary to answer the original request. Attackers controlling DNS responses can include CNAME records in the authority or additional sections, or outside the original query name's CNAME chain, causing excess resolver queries and increased query amplification.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| hickory-dns | hickory-dns | 0.25.0 – < 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-resolver | >= 0.25.0, < 0.26.2 | 0.26.2 | GHSA-6f2x-v7q7-m7m5 |
References
- GitHub Security Advisory (GHSA-6f2x-v7q7-m7m5) vendor-advisory
- VulnCheck Advisory: Hickory DNS 0.25.0 before 0.26.2 Query Amplification via Irrelevant CNAME Records third-party-advisory