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.
Race Condition Enabling Link Following
This weakness occurs when a program checks whether a file is safe to access for example, by verifying it's not a symbolic link pointing elsewhere, but an…
Time-of-check Time-of-use (TOCTOU) Race Condition
A TOCTOU race condition occurs when code checks a resource's state such as file permissions, account balance, or user role and then uses that resource later…
Divide By Zero
Divide by zero occurs when a program attempts to divide a number by zero, which is mathematically undefined. In most programming languages, this causes an…
Insecure Temporary File
Temporary files are often created with predictable names, world-readable permissions, or in shared directories where other users or processes can access or…
Creation of Temporary File With Insecure Permissions
This weakness occurs when a program creates a temporary file but fails to restrict access to it properly, leaving it readable or writable by other users on the…
Creation of Temporary File in Directory with Incorrect Permissions
This weakness occurs when an application creates temporary files in a directory that is world-readable or world-writable, allowing other users on the same…
Session Fixation
Session fixation is a vulnerability where an attacker tricks a user into logging in with a session ID that the attacker already knows. Because the application…
Detection of Error Condition Without Action
This weakness occurs when code detects that something has gone wrong—a failed authentication, a missing file, a database connection error—but then does nothing…
Unchecked Error Condition
This weakness occurs when code calls a function or performs an operation but fails to check whether it succeeded or failed. When errors go undetected, the…
Missing Report of Error Condition
This weakness occurs when software encounters an error but silently fails to log, report, or otherwise communicate that something went wrong. Without error…
Return of Wrong Status Code
This weakness occurs when software returns an HTTP status code or function return value that doesn't match the actual outcome of an operation. For example…
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption occurs when an application fails to limit how much of a shared resource—such as memory, CPU time, disk space, or network…
Missing Release of Memory after Effective Lifetime
A memory leak occurs when a program allocates memory but fails to release it after it is no longer needed. Over time, this causes memory consumption to grow…
Transmission of Private Resources into a New Sphere ('Resource Leak')
Resource leak occurs when a program makes a private resource—such as a file handle, memory segment, database connection, or temporary file—accessible to a…
Improper Resource Shutdown or Release
This weakness occurs when software fails to properly close or release resources—such as file handles, database connections, network sockets, or locks—after…
Asymmetric Resource Consumption (Amplification)
This weakness occurs when a small, inexpensive action by an attacker triggers a much larger consumption of server resources, creating a denial-of-service…
Insufficient Control of Network Message Volume (Amplification)
This weakness occurs when software responds to incoming network requests by generating disproportionately large or numerous outbound messages without proper…
Inefficient Algorithmic Complexity
This weakness occurs when software uses an algorithm that consumes disproportionate CPU, memory, or time relative to the size of its input. An attacker can…
Improper Handling of Highly Compressed Data
This weakness occurs when software decompresses data without validating the compression ratio or limiting resource consumption during decompression. An…
Insufficient Resource Pool
This weakness occurs when an application fails to properly size, limit, or manage its resource pools—such as database connections, thread pools, or memory…
Double Free
A double free occurs when a program attempts to deallocate the same memory address twice. This corrupts the memory allocator's internal bookkeeping…
Use After Free
Use After Free occurs when a program continues to reference memory that has already been freed and returned to the system. This can cause the application to…
Race Condition During Access to Alternate Channel
This weakness occurs when software protects a resource through one access path but leaves an alternate path unprotected or inadequately secured. An attacker…
Direct Request ('Forced Browsing')
Direct Request, also called forced browsing, occurs when a web application fails to properly check whether a user has permission to access a specific URL…
Untrusted Search Path
Untrusted Search Path occurs when an application searches for executables, libraries, or other critical resources using a path that an attacker can influence…
Uncontrolled Search Path Element
This weakness occurs when an application searches for files, libraries, or other resources using a path that includes directories controlled by an untrusted…
Unquoted Search Path or Element
This weakness occurs when a program searches for or executes files using a path that is not properly quoted, allowing an attacker to inject and execute a…
Unrestricted Upload of File with Dangerous Type
This weakness occurs when a web application accepts file uploads without properly validating the file type, allowing an attacker to upload executable scripts…
Interpretation Conflict
An interpretation conflict occurs when different components in a system parse or understand the same input in incompatible ways. A security control such as a…
Unintended Proxy or Intermediary ('Confused Deputy')
A \"Confused Deputy\" vulnerability occurs when a trusted application or service is tricked into performing actions on behalf of an attacker, rather than the…
