CVE-2026-22866

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.
Configurations

Configuration 1 (hide)

cpe:2.3:a:ens.domains:ethereum_name_service:*:*:*:*:*:*:*:*

History

13 Mar 2026, 01:02

Type Values Removed Values Added
Summary
  • (es) El Servicio de Nombres de Ethereum (ENS) es un sistema de nombres distribuido, abierto y extensible basado en la cadena de bloques de Ethereum. En las versiones 1.6.2 y anteriores, los contratos 'RSASHA256Algorithm' y 'RSASHA1Algorithm' no logran validar la estructura de relleno PKCS#1 v1.5 al verificar firmas RSA. Los contratos solo verifican si los últimos 32 (o 20) bytes de la firma descifrada coinciden con el hash esperado. Esto permite el ataque de falsificación de firmas de Bleichenbacher de 2006 contra zonas DNS que utilizan claves RSA con exponentes públicos bajos (e=3). Dos TLDs compatibles con ENS (.cc y .name) usan e=3 para sus Claves de Firma de Claves, permitiendo que cualquier dominio bajo estos TLDs sea reclamado fraudulentamente en ENS sin la propiedad de DNS. Un parche fue fusionado en el commit c76c5ad0dc9de1c966443bd946fafc6351f87587. Posibles soluciones provisionales incluyen desplegar los contratos parcheados y apuntar DNSSECImpl.setAlgorithm al contrato desplegado.
References () https://github.com/ensdomains/ens-contracts-bug-62248-pr-509 - () https://github.com/ensdomains/ens-contracts-bug-62248-pr-509 - Patch, Release Notes
References () https://github.com/ensdomains/ens-contracts/commit/c76c5ad0dc9de1c966443bd946fafc6351f87587 - () https://github.com/ensdomains/ens-contracts/commit/c76c5ad0dc9de1c966443bd946fafc6351f87587 - Patch
References () https://github.com/ensdomains/ens-contracts/security/advisories/GHSA-c6rr-7pmc-73wc - () https://github.com/ensdomains/ens-contracts/security/advisories/GHSA-c6rr-7pmc-73wc - Patch, Vendor Advisory
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 7.5
First Time Ens.domains ethereum Name Service
Ens.domains
CPE cpe:2.3:a:ens.domains:ethereum_name_service:*:*:*:*:*:*:*:*

25 Feb 2026, 16:23

Type Values Removed Values Added
New CVE

Information

Published : 2026-02-25 16:23

Updated : 2026-03-13 01:02


NVD link : CVE-2026-22866

Mitre link : CVE-2026-22866

CVE.ORG link : CVE-2026-22866


JSON object : View

Products Affected

ens.domains

  • ethereum_name_service
CWE
CWE-347

Improper Verification of Cryptographic Signature