ensdomains ens-contracts up to 1.6.2 signature verification

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k0.00

Summaryinfo

A vulnerability has been found in ensdomains ens-contracts up to 1.6.2 and classified as problematic. This issue affects some unknown processing. This manipulation causes signature verification. This vulnerability is handled as CVE-2026-22866. The attack can be initiated remotely. There is not any exploit available. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability has been found in ensdomains ens-contracts up to 1.6.2 and classified as problematic. Affected by this vulnerability is an unknown part. The manipulation with an unknown input leads to a signature verification vulnerability. The CWE definition for the vulnerability is CWE-347. The product does not verify, or incorrectly verifies, the cryptographic signature for data. As an impact it is known to affect integrity. The summary by CVE is:

Ethereum Name Service (ENS) is a distributed, open, and extensible naming system based on the Ethereum blockchain. In versions 1.6.2 and prior, the `RSASHA256Algorithm` and `RSASHA1Algorithm` contracts fail to validate PKCS#1 v1.5 padding structure when verifying RSA signatures. The contracts only check if the last 32 (or 20) bytes of the decrypted signature match the expected hash. This enables Bleichenbacher's 2006 signature forgery attack against DNS zones using RSA keys with low public exponents (e=3). Two ENS-supported TLDs (.cc and .name) use e=3 for their Key Signing Keys, allowing any domain under these TLDs to be fraudulently claimed on ENS without DNS ownership. Apatch was merged at commit c76c5ad0dc9de1c966443bd946fafc6351f87587. Possible workarounds include deploying the patched contracts and pointing DNSSECImpl.setAlgorithm to the deployed contract.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-22866 since 01/12/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available.

Applying the patch c76c5ad0dc9de1c966443bd946fafc6351f87587 is able to eliminate this problem. The bugfix is ready for download at github.com.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Signature verification
CWE: CWE-347 / CWE-345
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: c76c5ad0dc9de1c966443bd946fafc6351f87587

Timelineinfo

01/12/2026 CVE reserved
02/25/2026 +44 days Advisory disclosed
02/25/2026 +0 days VulDB entry created
03/13/2026 +16 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-c6rr-7pmc-73wc
Status: Confirmed

CVE: CVE-2026-22866 (🔒)
GCVE (CVE): GCVE-0-2026-22866
GCVE (VulDB): GCVE-100-347791

Entryinfo

Created: 02/25/2026 17:35
Updated: 03/13/2026 02:39
Changes: 02/25/2026 17:35 (68), 02/28/2026 20:54 (1), 03/13/2026 02:39 (12)
Complete: 🔍
Cache ID: 216::103

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