Common Weakness Enumeration — the root causes behind every CVE
CWE catalogs the root causes behind CVEs — SQL injection, XSS, broken auth, and 300+ others that keep showing up in security advisories. Each entry here covers how it happens, what it costs when someone exploits it, and the fix that actually closes it.
Use of GET Request Method With Sensitive Query Strings
This weakness occurs when a web application transmits sensitive data passwords, tokens, personal information as part of a GET request's query string. Because…
URL Redirection to Untrusted Site (Open Redirect)
An open redirect occurs when a web application takes user input and uses it to redirect the browser to another URL without validating that the destination is…
Improper Restriction of XML External Entity Reference
XML External Entity XXE injection occurs when an application parses untrusted XML input without disabling external entity resolution. An attacker can craft…
Insufficient Session Expiration
Session expiration is the mechanism that automatically logs out a user after a period of inactivity or elapsed time. When this is not properly implemented, an…
Sensitive Cookie in HTTPS Session Without 'Secure' Attribute
This weakness occurs when a web application sets a sensitive cookie such as a session token or authentication credential over HTTPS but fails to include the…
Unverified Password Change
This weakness occurs when a system allows a user's password to be changed without confirming the user's identity first — typically by requiring the current…
Executable Regular Expression Error
This weakness occurs when a regular expression engine evaluates code embedded within a regex pattern or subject string, rather than treating the pattern as a…
Permissive Regular Expression
A permissive regular expression accepts a wider range of input than intended, allowing malicious or unexpected data to pass validation checks. This weakness…
Authorization Bypass Through User-Controlled Key
This weakness occurs when an application allows users to directly control identifiers like user IDs, account numbers, or resource IDs in requests, without…
Weak Password Recovery Mechanism for Forgotten Password
Password recovery mechanisms are often the weakest link in account security. When a site uses easily guessable security questions, sends recovery codes via…
Improper Restriction of Names for Files and Other Resources
This weakness occurs when an application allows users to specify or influence the names of files, directories, or other resources without proper validation or…
Improper Neutralization of Data within XPath Expressions
XPath injection occurs when user-supplied input is directly embedded into an XPath query without proper escaping or validation. An attacker can inject XPath…
Improper Neutralization of HTTP Headers for Scripting Syntax
This weakness occurs when an application accepts user-controlled data in HTTP headers and passes it to a downstream component such as a template engine…
Reliance on File Name or Extension of Externally-Supplied File
This weakness occurs when an application trusts a file's name or extension to determine how it should be processed, without verifying the actual file content…
Incorrect Use of Privileged APIs
This weakness occurs when code calls security-critical functions like permission checks, cryptographic operations, or system calls but fails to use them…
Reliance on Obfuscation or Encryption without Integrity Checking
This weakness occurs when software encrypts or obfuscates data but fails to verify that the data hasn't been modified after encryption. An attacker can alter…
Trusting HTTP Permission Methods on the Server Side
This weakness occurs when a web application relies solely on HTTP method restrictions GET, POST, PUT, DELETE, etc. to enforce security controls, without…
Insufficient Compartmentalization
Insufficient compartmentalization occurs when a software system fails to isolate components or functionality that operate at different privilege levels or…
Reliance on a Single Factor in a Security Decision
This weakness occurs when software makes a security decision based on only one piece of evidence—such as a single password, a single token, or a single…
Violation of Secure Design Principles
This weakness describes software that is built on an insecure architectural foundation — one that ignores established principles like least privilege, defense…
Improper Control of a Resource Through its Lifetime
This weakness occurs when software fails to properly manage a resource—such as memory, a file handle, a database connection, or a temporary credential—from the…
Improper Initialization
Improper initialization occurs when a software component fails to set up a resource—such as a variable, array, object, or connection—to a known safe state…
Operation on Resource in Wrong Phase of Lifetime
This weakness occurs when code attempts to use a resource memory, file handle, database connection, etc. at an inappropriate point in its lifecycle — before it…
Improper Locking
Improper locking occurs when software fails to correctly acquire or release locks on shared resources accessed by multiple threads or processes. This weakness…
Exposure of Resource to Wrong Sphere
This weakness occurs when a resource—such as a file, database, API endpoint, or configuration—is made accessible to users or systems that should not have…
Incorrect Resource Transfer Between Spheres
This weakness occurs when software fails to properly hand off control of a resource—such as a file handle, memory buffer, or database connection—between…
Always-Incorrect Control Flow Implementation
This weakness occurs when a program contains a control flow path—a sequence of conditional branches or loops—that is logically flawed and never executes as…
Operation on a Resource after Expiration or Release
This weakness occurs when code attempts to use a resource—such as memory, a file handle, a database connection, or a session token—after that resource has been…
Uncontrolled Recursion
Uncontrolled recursion occurs when a program calls itself repeatedly without a proper limit, allowing an attacker to exhaust the call stack and crash the…
Duplicate Operations on Resource
This weakness occurs when software performs the same operation on a resource multiple times when it should only happen once. Common examples include charging a…
