CVE-2026-123588
Hickory DNS Recursive Resolver Denial of Service via Cached Empty Connection Pool
CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th
The recursive resolver in Hickory DNS (all versions of the hickory-recursor crate, and hickory-resolver 0.26.0 before 0.26.2) caches an empty connection pool when it follows a referral with no glue records and all queries for the name servers' IP addresses fail. An attacker able to spoof DNS responses can make these lookups fail, causing all subsequent queries for the affected zone to fail until the cache entry expires or is evicted.
| CWE | CWE-754 |
| Vendor | hickory-dns |
| Product | hickory-dns |
| Published | Nov 8, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
hickory-dns / hickory-dns
0 ≤ 0.26.0-alpha.1
hickory-dns / hickory-dns
0.26.0 < 0.26.2
References
Credits
🔍 qifan-sailboat