A critical vulnerability, CVE-2025-47949, has emerged in samlify, a widely used Node.js library that implements SAML 2.0 Single Sign-On (SSO). This flaw, known as a Signature Wrapping attack, allows attackers to forge authentication responses, bypassing login protections and potentially impersonating any user, including administrators.

Understanding the Vulnerability

The flaw affects samlify versions prior to 2.10.0 and stems from improper verification of XML signatures. In a standard SAML SSO process, Identity Providers (IdPs) sign XML assertions to validate a user’s identity. This vulnerability lets attackers inject malicious assertions into a signed response. Because vulnerable versions of samlify fail to validate the full XML structure, they may accept the attacker's data as legitimate.

No special privileges or user interaction are required, making exploitation relatively easy—especially if the attacker can intercept or obtain a signed XML response. Given samlify’s popularity (over 200,000 weekly downloads on npm), the potential impact is broad.

The Ripple Effect of Third-Party Vulnerabilities

Third-party vulnerabilities like this one can affect your application even if you don't directly depend on the vulnerable package. If any dependency in your software stack includes samlify, you're potentially at risk. Traditional scanners often miss or overload teams with such nested vulnerabilities, leaving critical gaps unresolved.

How Seal Security Helps Mitigate These Risks

Seal Security is designed for rapid, practical remediation without disrupting your workflow:

• Automated Vulnerability Detection: Seal uncovers vulnerabilities across your entire dependency graph, including deeply nested transitive dependencies. CVE-2025-47949 is surfaced immediately, even if buried deep in your stack.
  
  
• One-Click Patching Without Breaking Changes: Instead of requiring risky version upgrades, Seal provides security-specific patches that work with your existing versions—mitigating the risk instantly.
  
  
• Transitive Dependency Patching: Seal goes beyond surface-level scanning by providing fix-ready patches for both direct and transitive dependencies. This ensures vulnerabilities like CVE-2025-47949 are resolved even when introduced indirectly through your software supply chain.

• Independent Remediation: Security teams can apply patches directly, without waiting on developers. This reduces Mean-Time-To-Remediation (MTTR) and accelerates response across legacy and modern systems alike.
  
  
• Continuous Monitoring: Seal continuously monitors your environment and delivers patches as soon as new vulnerabilities are identified, minimizing the window of exposure.
  
  

Immediate Steps for AppSec Teams

To protect your applications from CVE-2025-47949:

• Upgrade to samlify version 2.10.0 or later, if possible.
  
  
• If not, implement Seal Security to patch the vulnerability without disrupting your application.
  
  
• Review your full dependency graph to check for indirect exposure.
  
  

Take Action Today

CVE-2025-47949 is a stark reminder of the security risks lurking in third-party dependencies. With Seal Security, you can detect and remediate vulnerabilities quickly, without relying on major upgrades or overburdening your developers.

Take control of your open source risk. Secure your dependencies, streamline compliance, and strengthen your application’s security posture with Seal Security.

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