Quick answers
- Is This vulnerability exploited in the wild?
- No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.
- How severe is This vulnerability?
- Medium severity, published 5 October 2026.
- Which products and versions are affected?
- hickory-resolver (crates.io) >= 0.25.0, < 0.26.2; Hickory-Dns Hickory-Resolver >= 0.25.0, < 0.26.2.
- Is there a fix for This vulnerability?
- Yes: fixed in 0.26.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is This vulnerability attacked?
- It is attacked over the network.
- Am I affected?
- Check whether you run hickory-resolver (crates.io) or Hickory-Dns Hickory-Resolver at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: 0.26.2
Technical details
The vulnerability is an uncontrolled resource consumption issue (CWE-400) where hickory-resolver follows CNAME records that appear in the authority or additional sections of DNS responses, even when they are not part of the chain needed to resolve the original query. This causes unnecessary DNS queries to be sent over the network. An attacker can craft malicious DNS responses with unrelated CNAME records to trigger query amplification, exploitable remotely via the network without authentication.
Affected products
- hickory-dns hickory-resolver >= 0.25.0, < 0.26.2
Timeline
- 2026-09-03: disclosed
- 2026-10-05: advisory