CVE-2026-22866 Security Details

CVE ID

CVE-2026-22866

CWE

CWE-347

CVE 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.

Published

Feb 26, 2026

CVSS Score & Severity

7.5High

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Score

0.015%

Malware

malware

KEV Status

Not in KEV Catalog: No known exploits

Affected Ecosystems

affected

Source

National Vulnerability Database

References

https://github.com/advisories/GHSA-c6rr-7pmc-73wcTHIRD_PARTY