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.
References
| Link | Resource |
|---|---|
| https://github.com/ensdomains/ens-contracts-bug-62248-pr-509 | Patch Release Notes |
| https://github.com/ensdomains/ens-contracts/commit/c76c5ad0dc9de1c966443bd946fafc6351f87587 | Patch |
| https://github.com/ensdomains/ens-contracts/security/advisories/GHSA-c6rr-7pmc-73wc | Patch Vendor Advisory |
Configurations
History
13 Mar 2026, 01:02
| Type | Values Removed | Values Added |
|---|---|---|
| Summary |
|
|
| References | () https://github.com/ensdomains/ens-contracts-bug-62248-pr-509 - Patch, Release Notes | |
| References | () https://github.com/ensdomains/ens-contracts/commit/c76c5ad0dc9de1c966443bd946fafc6351f87587 - Patch | |
| References | () https://github.com/ensdomains/ens-contracts/security/advisories/GHSA-c6rr-7pmc-73wc - Patch, Vendor Advisory | |
| CVSS |
v2 : v3 : |
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
