CVSS Score Calculator 2025 | Common Vulnerability Scoring System

Assess vulnerability severity with our free CVSS score calculator. This professional tool calculates CVSS v3.1 base scores, temporal scores, and environmental scores according to official FIRST standards for accurate vulnerability prioritization.

How Our CVSS Score Calculator Works

This CVSS v3.1 score calculator implements the official Common Vulnerability Scoring System formulas from FIRST to assess vulnerability severity:

• Calculates base scores using 8 fundamental metrics
• Determines severity ratings from None to Critical
• Generates vector strings for standardized reporting
• Computes subscores for impact and exploitability
• Adjusts for temporal/environmental factors

Understanding CVSS Scores

The Common Vulnerability Scoring System is the industry standard for assessing vulnerability severity:

Base Metrics

• Attack Vector (AV): How the vulnerability is exploited (Network, Adjacent, Local, Physical)
• Attack Complexity (AC): Conditions beyond attacker's control
• Privileges Required (PR): Level of access needed
• User Interaction (UI): Requires user action?

Impact Metrics

• Confidentiality (C): Information disclosure impact
• Integrity (I): Data tampering impact
• Availability (A): Service disruption impact
• Scope (S): Does it affect other components?

CVSS Severity Ratings

Our CVSS base score calculator categorizes vulnerabilities according to these ranges:

• 9.0-10.0 (Critical): Easily exploitable with devastating impact
• 7.0-8.9 (High): Significant organizational risk
• 4.0-6.9 (Medium): Moderate risk requiring attention
• 0.1-3.9 (Low): Minimal impact or difficult to exploit
• 0.0 (None): No security impact

How CVSS Scores Are Calculated

The CVSS score calculation process involves these key steps:

1. Assess exploitability metrics: AV, AC, PR, UI
2. Evaluate impact metrics: C, I, A considering scope
3. Calculate Impact Subscore: Based on CIA impacts
4. Calculate Exploitability Subscore: Based on attack requirements
5. Compute Base Score: Combine impact and exploitability
6. Adjust for temporal factors: Exploit availability, fixes
7. Modify for environment: Organizational-specific impacts

When to Use CVSS Scoring

Our CVSS v3 score calculator helps with these security activities:

• Vulnerability management: Prioritize patching efforts
• Risk assessment: Quantify potential impact
• Security reporting: Standardized metrics for stakeholders
• Compliance documentation: Demonstrate risk awareness
• Vendor evaluations: Compare product security postures

Common CVSS Calculation Mistakes

Even with a good CVSS calculator, watch for these errors:

• Misunderstanding Scope: Changed vs. Unchanged confusion
• Overlooking Privileges Required: Difference between Low and High
• Ignoring User Interaction: Many vulnerabilities require user action
• Inconsistent Impact Ratings: Overestimating CIA impacts
• Forgetting Environmental Factors: Not adjusting for organizational context

Frequently Asked Questions

What's the difference between CVSS v3 and v3.1?

CVSS v3.1, calculated by our CVSS score calculator 3.1, includes clarifications for Scope, User Interaction, and Privileges Required metrics but uses the same formulas as v3.0.

How often should CVSS scores be updated?

Base scores typically remain stable, but temporal scores should be updated as new exploit code becomes available or patches are released.

What's a good CVSS score threshold for patching?

Most organizations prioritize vulnerabilities with scores ≥7.0 (High), but your threshold should depend on risk tolerance and asset criticality.

Can CVSS scores exceed 10.0?

No, the maximum CVSS score is 10.0. Our calculate CVSS score tool properly caps results at this maximum.

CVSS Resources

For more information on CVSS scoring:

• FIRST CVSS v3.1 Specification (https://www.first.org/cvss)
• NVD CVSS Calculator (https://nvd.nist.gov/vuln-metrics/cvss)
• CVSS Examples (https://www.first.org/cvss/examples)