CVE-2026-123603

MEDIUM
MEDIUM Priority: 0.01 BB Relevance: 74/100
Published: 2026-11-08 Modified: 2026-11-08 First seen: 2026-11-08 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: X
AT: None
VC: Low
VI: Low
VA: None

Description

hickory-proto and hickory-resolver 0.26.0 before 0.26.2, hickory-server 0.25.0-alpha.1 before 0.26.2, and hickory-recursor 0.25.0-alpha.3 through 0.26.0-alpha.1 fail to canonicalize IPv4-mapped IPv6 addresses when checking deny_answers, deny_server, or AccessControlSet rules. Attackers can use IPv4-mapped addresses to evade answer filtering, trigger queries to denied nameservers, or reach hickory-server library deployments on dual-stack IPv6 sockets from denied clients.

Weakness Classification (1)

Affected Software (4)

VendorProductVersion
hickory-dns hickory-dns 0.25.0-alpha.3
hickory-dns hickory-dns 0.26.0 < 0.26.2
hickory-dns hickory-dns 0.26.0 < 0.26.2
hickory-dns hickory-dns 0.25.0-alpha.1 < 0.26.2

Bug Bounty Relevance

74 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

6.9 / 10.0 v4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.17%
Raw Score 0.001660
Percentile 5.8%
Date 2026-11-08

Intelligence Sources

mitre ref →
nvd ref →