Fix it in your stack

Tested fixes for CWE-1333 in Express, Flask, Spring Boot and ASP.NET Core: the vulnerable code, the fix, a plausible fix that still fails, and the regression tests.

What MITRE says

The description above is MITRE’s definition of CWE-1333 in CWE 4.20, a base-level weakness.

Common consequences MITRE lists

  • Availability: DoS: Resource Consumption (CPU)

Guides on this site

Cites this weakness · Guide

Validate input safely and prevent regex denial of service

Find and fix exponential and quadratic regex backtracking with measured examples, choose linear-time engines or timeouts, and build allowlist validation that decodes once and rejects type confusion and parameter pollution.

References

  1. CWE-1333 in the MITRE CWE list (version 4.20)

This page is generated from MITRE’s CWE 4.20 catalogue (released 30 April 2026) and lists every guide, fix card and lab here that cites CWE-1333.

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