VulnerabilityPublished 8 Nov 2026

CVE-2026-123580: hickory-dns · Authentication Bypass by Spoofing

Affects hickory-dnsSource CVE Database V5

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Not known to be exploited · CVSS 8.7 High : upgrade to 0.26.2 soon.

Data as of 8 Nov 2026, 02:03 UTC

CVSS 4.0 base score

8.7High

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (VulnCheck)	CVSS 4.0	8.7
CNA (VulnCheck)	CVSS 3.1	7.5

Patch: Available – fixed in 0.26.2

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

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: High
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the vulnerable system. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the vulnerable system.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 8 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 7 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade hickory-dns to 0.26.2.

Affected software

Product	Affected	Fixed in
hickory-dnshickory-dns	Affected >=0.26.0-beta.1 <0.26.2	Fixed in 0.26.2
hickory-dnshickory-dns	Affected <=0.26.0-alpha.1	Fixed in–
crates.iohickory-dns`pkg:cargo/hickory-dns`Other threats	Affected >=0.26.0-beta.1 <0.26.2 <=0.26.0-alpha.1	Fixed in 0.26.2

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available in Hickory DNS version 0.26.2. Users should upgrade to version 0.26.2 or later to remediate this vulnerability. No additional mitigations are indicated by the vendor advisory.

Description

CVE-2026-123580 is an authentication bypass vulnerability in Hickory DNS affecting versions 0.26.0-beta.1 through before 0.26.2 and hickory-proto through 0.26.0-alpha.1. The flaw arises from insufficient validation of NSEC3 record names during DNSSEC verification, where only the hashed label is checked without confirming the record's zone membership. This allows attackers to forge DNSSEC nonexistence proofs by supplying NSEC3 records from other zones with matching hash labels.

Impact

Successful exploitation allows attackers to forge DNSSEC nonexistence proofs, potentially causing resolvers to incorrectly validate DNS responses as authentic when they are not. This undermines DNSSEC's security guarantees, leading to possible DNS spoofing or cache poisoning attacks. The CVSS 4.0 score of 8.7 (high severity) reflects the network attack vector, low complexity, no privileges or user interaction required, and high impact on integrity.

Summary

Hickory DNS versions 0.26.0-beta.1 up to but not including 0.26.2 and hickory-proto up to 0.26.0-alpha.1 perform inadequate verification of NSEC3 record names during DNSSEC validation. Specifically, the software compares only the hashed label portion of the NSEC3 record name without verifying that the record belongs to the correct DNS zone. This weakness enables attackers to spoof DNSSEC nonexistence proofs by providing NSEC3 records from a different zone that share the same hashed label, effectively bypassing DNSSEC authentication.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 8 Nov 2026, 02:03 UTC

Technical details

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