CVE-2026-22866: @ensdomains/ens contracts ENS DNSSEC Oracle Vulnerable To Vulnerability
LOWCVE-2026-22866 is a LOW ens dnssec oracle vulnerable to vulnerability (CWE-347: Improper Verification of Cryptographic Signature) affecting @ensdomains/ens contracts libraries in the npm ecosystem. The issue involves ens dnssec oracle vulnerable to rsa signature forgery via missing pkcs#1 v1.5 padding validation. Remediation is available in the latest vendor maintenance releases.
CVE-2026-22866 at a Glance
How to Fix CVE-2026-22866
To remediate this vulnerability, upgrade all affected @ensdomains/ens contracts dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
npm install @ensdomains/ens-contracts@Latest secure releaseRun the following command in your project directory to verify that all resolved dependencies use the patched release:
npm ls @ensdomains/ens-contractsHow to Check if You Are Affected
To determine whether your Node.js application is affected by CVE-2026-22866, inspect your project dependencies using npm:
npm ls @ensdomains/ens-contractsAnalyze the terminal output to locate any version of @ensdomains/ens contracts in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.
Note: The npm ls @ensdomains/ens-contracts command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-347: Improper Verification of Cryptographic Signature, where the product does not verify, or incorrectly verifies, the cryptographic signature for data. In @ensdomains/ens contracts, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-22866 Affected @ensdomains/ens contracts Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
@ensdomains/ens-contracts
|
npm |
≤ 1.6.2
|
|
References
Frequently Asked Questions
What is CVE-2026-22866?
Which @ensdomains/ens contracts versions are affected?
What version fixes CVE-2026-22866?
Is @ensdomains/ens-contracts affected?
What CWE is associated with CVE-2026-22866?
How can I check npm dependencies for CVE-2026-22866?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-c6rr-7pmc-73wc",
"modified" : "2026-02-27T20:55:13Z",
"published" : "2026-02-25T18:26:58Z",
"aliases" : [ "CVE-2026-22866" ],
"summary" : "ENS DNSSEC Oracle Vulnerable to RSA Signature Forgery via Missing PKCS#1 v1.5 Padding Validation",
"details" : "### Impact\n\nThe `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.\n\nAffected contracts\n\nContract | Address | Status\n-- | -- | --\nRSASHA256Algorithm | 0x9D1B5a639597f558bC37Cf81813724076c5C1e96 | Vulnerable\nRSASHA1Algorithm | 0x6ca8624Bc207F043D140125486De0f7E624e37A1 | Vulnerable\nDNSSECImpl | 0x0fc3152971714E5ed7723FAFa650F86A4BaF30C5 | Uses vulnerable algorithms\nDNSRegistrar | 0xB32cB5677a7C971689228EC835800432B339bA2B | Attack entry point\n\n\n\n\n### Patches\n\nThe bug was reported via Immunefi with possible solutions. The patch was merged at https://github.com/ensdomains/ens-contracts/commit/c76c5ad0dc9de1c966443bd946fafc6351f87587\n\n\n### Workarounds\n\n- Deploy the patched contracts\n- Point DNSSECImpl.setAlgorithm to the deployed contract\n\n### Resources\n\nhttps://github.com/ensdomains/ens-contracts-bug-62248-pr-509",
"severity" : [ {
"type" : "CVSS_V4",
"score" : "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"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "npm",
"name" : "@ensdomains/ens-contracts"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"last_affected" : "1.6.2"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/ensdomains/ens-contracts/security/advisories/GHSA-c6rr-7pmc-73wc"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-22866"
}, {
"type" : "WEB",
"url" : "https://github.com/ensdomains/ens-contracts/commit/c76c5ad0dc9de1c966443bd946fafc6351f87587"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/ensdomains/ens-contracts"
}, {
"type" : "WEB",
"url" : "https://github.com/ensdomains/ens-contracts-bug-62248-pr-509"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-347" ],
"severity" : "LOW",
"github_reviewed" : true,
"github_reviewed_at" : "2026-02-25T18:26:58Z",
"nvd_published_at" : "2026-02-25T16:23:25Z"
}
}