CVE-2026-22866

LOW EPSS 7.4%
Published Feb 25, 20264mo ago · Modified Jun 17, 20262w ago
2.7 CVSS 4.0
Low
Find Similar
Published Feb 25, 2026 4mo ago
Last Modified Jun 17, 2026 2w ago

Description

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.

CVSS Details

Base Score
2.7
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/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
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
7.4% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-347

Affected Products 1

VendorProductVersionRange
ens.domainsethereum_name_service* ≤1.6.2

References 3

  • github.com https://github.com/ensdomains/ens-contracts-bug-62248-pr-509
    PatchRelease Notes
  • github.com https://github.com/ensdomains/ens-contracts/commit/c76c5ad0dc9de1c966443bd946fafc6351f87587
    Patch
  • github.com https://github.com/ensdomains/ens-contracts/security/advisories/GHSA-c6rr-7pmc-73wc
    PatchVendor Advisory

Remediation

  • github.com https://github.com/ensdomains/ens-contracts-bug-62248-pr-509
    PatchRelease Notes
  • github.com https://github.com/ensdomains/ens-contracts/commit/c76c5ad0dc9de1c966443bd946fafc6351f87587
    Patch
  • github.com https://github.com/ensdomains/ens-contracts/security/advisories/GHSA-c6rr-7pmc-73wc
    PatchVendor Advisory