Sources: National Vulnerability Database, CVE.org, CISA KEV, FIRST EPSS
CVE-2026-123605 Overview
Hickory DNS hickory-proto 0.1 through 0.25.0-alpha.3 and hickory-net before 0.26.2 contain a DNSSEC validation bypass because the validator verifies an RRSIG against the DNSKEY of whatever name appears in its Signer's Name field without checking that this name is the zone containing the RRset. Attackers controlling any secure zone can produce valid signatures over arbitrary records in unrelated zones, which resolvers, recursors, and clients using DnssecDnsHandle accept as authenticated.
Critical Impact
Affected Products
- Hickory DNS hickory-proto: see the vendor advisory for the exact affected versions
Discovery Timeline
- 2026-11-08: CVE-2026-123605 published to the National Vulnerability Database by disclosure@vulncheck.com
- 2026-11-08: last updated in the NVD database
Technical Details for CVE-2026-123605
Vulnerability Analysis
CVE-2026-123605 is a Security Vulnerability weakness (CWE-347) in Hickory DNS hickory-proto. Based on its CVSS vector, the flaw can be reached over the network, needs some level of access, and needs no user interaction.
With a CVSS base score of 8.7, apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Root Cause
The vendor description states: Hickory DNS hickory-proto 0.1 through 0.25.0-alpha.3 and hickory-net before 0.26.2 contain a DNSSEC validation bypass because the validator verifies an RRSIG against the DNSKEY of whatever name appears in its Signer's Name field without checking that this name is the zone containing the RRset. Attackers controlling any secure zone can produce valid signatures over arbitrary records in unrelated zones, which resolvers, recursors, and clients using DnssecDnsHandle accept as authenticated.
Attack Vector
Based on the CVSS vector, the flaw can be reached over the network, needs some level of access, and needs no user interaction. Attack complexity is low complexity.
No exploitation in the wild is confirmed by CISA at the time of the last update. Check the references below for any vendor or researcher proof of concept.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/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
Detection Methods for CVE-2026-123605
Detection Strategies
- Inventory every instance of Hickory DNS hickory-proto and compare the running version with the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Run an authenticated vulnerability scan once your scanner ships a check for this CVE.
Monitoring Recommendations
- Forward Hickory DNS hickory-proto application, access and audit logs to your SIEM for retrospective hunting.
- Alert on new processes, configuration changes or outbound connections from the affected service.
- Track the vendor advisory and the CISA KEV catalog for changes in exploitation status.
How to Mitigate CVE-2026-123605
Immediate Actions Required
- Apply the fixed version of Hickory DNS hickory-proto named in the vendor advisory.
- Prioritize internet facing and business critical instances first.
- Rescan after the change to confirm the exposure is closed.
Patch Information
Use the fixed version listed in the vendor advisory for Hickory DNS hickory-proto.
Workarounds
- If patching must wait, restrict network access to the affected service and place it behind authentication or a web application firewall rule.
CWE References
Technical References
This entry is built directly from NVD, CISA KEV and EPSS data. Verify fixed versions in the vendor advisory before you deploy.
Frequently asked questions
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