Revise vulnerability notice for ruby-saml

Updated vulnerability notice to reflect affected versions.

Author: pitbulk

README.md

@@ -10,7 +10,7 @@ Minor and patch versions of Ruby SAML may introduce breaking changes. Please rea
 
 ## Vulnerability Notice
 
-[CVE-2025-66568](https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3) and [CVE-2025-66567](https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3) affects version ruby-saml <= 1.12.4, upgrade to 1.18.1
+[CVE-2025-66568](https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3) and [CVE-2025-66567](https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3) affects version ruby-saml < 1.18.0 (including 1.12.4), upgrade to 1.18.1
 
 CVE-2025-54572 affects version ruby-saml < 1.18.1