CVE-2026-123588

high

Description

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.

References

https://www.vulncheck.com/advisories/hickory-dns-recursive-resolver-denial-of-service-via-cached-empty-connection-pool

https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-9px7-7m25-f6q2

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-119347

Details

Source: Mitre, NVD

Published: 2026-11-08

Updated: 2026-11-08

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: High

CVSS v4

Base Score: 8.7

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Severity: High

EPSS

EPSS: 0.00343