XSS Payload Pattern (Basic Detection) Regex for Go

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching xss payload pattern (basic detection), ported and verified for Go. In security-sensitive code, using an unverified regex can open the door to both false positives and denial-of-service attacks. The snippet below is ready to drop into your Go project — whether you're validating in a Gin handler, a gRPC service, or a command-line tool.

Go Implementation

// XSS Payload Pattern (Basic Detection)
// ReDoS-safe | RegexVault — Security > Injection Patterns

package validation

import "regexp"

var xssPayloadPatternBasicDetectionRe = regexp.MustCompile(`(?:<script[\s>]|<\/script>|javascript:|vbscript:|onload\s*=|onerror\s*=|onclick\s*=|onmouseover\s*=|<iframe\b|<object\b|<embed\b|<svg[\s>]|document\.cookie|document\.write|eval\s*\(|setTimeout\s*\(|setInterval\s*\(|window\.location|alert\s*\(|confirm\s*\(|prompt\s*\(|data:text/html)`)

func ValidateXssPayloadPatternBasicDetection(s string) bool {
    return xssPayloadPatternBasicDetectionRe.MatchString(s)
}

// Example
// fmt.Println(ValidateXssPayloadPatternBasicDetection("<script>alert(1)</script>")) // true

Test Cases

When to use this pattern

This pattern is drawn from the Security > Injection Patterns category and carries a ReDoS-safe certification. That matters for Go developers because Go's RE2 engine is inherently safe from catastrophic backtracking, but this pattern has been additionally verified for correctness. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

Basic XSS detection. Incomplete — XSS payloads can be encoded in dozens of ways (HTML entities, Unicode escapes, UTF-7, etc.). Use as a signal for logging/alerting. The real defense is output encoding via a template engine (React, Vue, Jinja2 with auto-escaping).