VulnerabilityPublished 18 Sep 2026Updated 21 Sep 2026

CVE-2026-93657: hickory-resolver · Improper Verification of Cryptographic Signature

Affects hickory-resolverSource 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 2 Nov 2026, 22:58 UTC

CVSS 4.0 base score

8.7High

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 13% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
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 18 Sep 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 2 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-resolver to 0.26.2.

Affected software

Product	Affected	Fixed in
hickory-dnshickory-resolver	Affected <0.26.2	Fixed in 0.26.2
crates.iohickory-resolver`pkg:cargo/hickory-resolver`Other threats	Affected <0.26.2	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

Upgrade hickory-resolver to version 0.26.2 or later, where this issue is fixed. No other mitigation is indicated by the vendor advisory. Patch status is confirmed by the presence of fixed version 0.26.2.

Description

hickory-resolver versions before 0.26.2 have a vulnerability where bogus DNSSEC proof states are not properly propagated through key resolver APIs. This flaw allows attackers controlling the DNS answering zone or positioned on the network path to have forged DNS records accepted as valid, bypassing DNSSEC authentication checks. The vulnerability has a high severity score of 8.7 and affects versions prior to 0.26.2.

Impact

The vulnerability allows attackers to bypass DNSSEC authentication checks, potentially causing clients to accept forged DNS records as legitimate. This can lead to DNS spoofing attacks, redirecting users to malicious sites or intercepting traffic. However, there are no known exploits in the wild at this time.

Summary

CVE-2026-93657 describes an improper verification of cryptographic signatures in hickory-resolver. Specifically, versions before 0.26.2 fail to propagate invalid DNSSEC proof states through the Resolver::lookup() and Resolver::lookup_ip() APIs. This allows attackers who control the DNS answering zone or are on the network path to inject forged DNS records that are accepted as valid, effectively bypassing DNSSEC authentication mechanisms.

References

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