Skip to content
Patch Next
Sign inAdd to your agent

← Actionable
Low, CVSS 2.7amended

ENS DNSSEC Oracle Vulnerable to RSA Signature Forgery via Missing PKCS#1 v1.5 Padding Validation

CVE-2026-22866GHSA-c6rr-7pmc-73wc

What to do

Vendor response not established. Follow the primary source's mitigation guidance and check back for a fix.

This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.

Add to your agent

Affected packages

  • npm @ensdomains/ens-contracts

    Affected
    <= 1.6.2
    Fixed in
    no fixed version recorded

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS 4.0
2.7 · 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 · score source
EPSS
  • CVE-2026-22866: 0.20% estimated exploitation activity in the next 30 days; percentile 10.07 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.
Source description

As published by the source; long descriptions are shortened.

Impact 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. Affected contracts Contract | Address | Status -- | -- | -- RSASHA256Algorithm | 0x9D1B5a639597f558bC37Cf81813724076c5C1e96 | Vulnerable RSASHA1Algorithm | 0x6ca8624Bc207F043D140125486De0f7E624e37A1 | Vulnerable DNSSECImpl | 0x0fc3152971714E5ed7723FAFa650F86A4BaF30C5 | Uses vulnerable algorithms DNSRegistrar | 0xB32cB5677a7C971689228EC835800432B339bA2B | Attack entry point Patches The bug was reported via Immunefi with possible solutions. The patch was…

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 3 · amended ·

    Amended from ghsa record GHSA-c6rr-7pmc-73wc

  2. Revision 2 · amended ·

    Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

  3. Revision 1 · created ·

    Published from osv record GHSA-c6rr-7pmc-73wc

Agent brief

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-22866

Advisory: ENS DNSSEC Oracle Vulnerable to RSA Signature Forgery via Missing PKCS#1 v1.5 Padding Validation
IDs: CVE-2026-22866, GHSA-c6rr-7pmc-73wc
Record: https://patchnext.com/advisories/cve-2026-22866 (revision 3, source checked 26 Oct 2026, 12:42 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 2.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @ensdomains/ens-contracts: affected <= 1.6.2

## Suggested inspection (read-only)
- `npm ls @ensdomains/ens-contracts --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on @ensdomains/ens-contracts.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-c6rr-7pmc-73wc (OSV record GHSA-c6rr-7pmc-73wc lists affected ranges: npm @ensdomains/ens-contracts >=0 <=1.6.2)
- Verified: https://github.com/advisories/GHSA-c6rr-7pmc-73wc (GitHub-reviewed advisory GHSA-c6rr-7pmc-73wc lists affected ranges: npm @ensdomains/ens-contracts >=0 <=1.6.2)

Commands are suggestions: review each one before running it.

Loading voting…