The product attempts to return a memory resource to the system, but it calls the wrong release function or calls the appropriate release function incorrectly.

What CVEs are caused by CWE-763?

38 recorded CVEs are attributed to CWE-763, including CVE-2026-52993, CVE-2026-22770, CVE-2024-44852.

How do you prevent CWE-763?

Only call matching memory management functions. Do not mix and match routines. For example, when you allocate a buffer with malloc(), dispose of the original pointer with free().

How is CWE-763 detected?

Fuzzing: Fuzz testing (fuzzing) is a powerful technique for generating large numbers of diverse inputs - either randomly or algorithmically - and dynamically invoking the code with those inputs. Even with random inputs, it is often capable of generating unexpected results such as crashes, memory corruption, or resource consumption. Fuzzing effectively produces repeatable test cases that clearly indicate bugs, which helps developers to diagnose the issues.

What are the consequences of CWE-763?

Exploiting CWE-763 can lead to: Modify Memory, DoS: Crash, Exit, or Restart, Execute Unauthorized Code or Commands.

Is CWE-763 actively exploited?

38 recorded CVEs are caused by CWE-763; none are currently in CISA's KEV catalog of actively exploited flaws.

CWE-763: Release of Invalid Pointer or Reference

RadicalNotion.AI

Code examples

Illustrative examples from MITRE showing how the weakness appears in code.

This code attempts to tokenize a string and place it into an array using the strsep function, which inserts a \0 byte in place of whitespace or a tab character. After finishing the loop, each string in the AP array points to a location within the input string.

Vulnerable example

char **ap, *argv[10], *inputstring;

Since strsep is not allocating any new memory, freeing an element in the middle of the array is equivalent to free a pointer in the middle of inputstring.

This example allocates a BarObj object using the new operator in C++, however, the programmer then deallocates the object using free(), which may lead to unexpected behavior.

Vulnerable example

cpp

void foo(){

Safe example

cpp

void foo(){

Instead, the programmer should have either created the object with one of the malloc family functions, or else deleted the object with the delete operator.

In this example, the programmer dynamically allocates a buffer to hold a string and then searches for a specific character. After completing the search, the programmer attempts to release the allocated memory and return SUCCESS or FAILURE to the caller. Note: for simplification, this example uses a hard-coded "Search Me!" string and a constant string length of 20.

Vulnerable example

#define SUCCESS (1)

Safe example

#define SUCCESS (1)

Consider the following code in the context of a parsing application to extract commands out of user data. The intent is to parse each command and add it to a queue of commands to be executed, discarding each malformed entry.

CWE-763: Release of Invalid Pointer or Reference

Overview

Real-world CVEs

Common consequences

How it happens

When it is introduced

Applies to

How to prevent it

How to detect it

Fuzzing

Automated Dynamic Analysis

Code examples

Illustrative examples

Terminology & mappings

Mapped taxonomies

Frequently asked questions

References

Stay ahead of CWE-763

Overview

Real-world CVEs

Common consequences

How it happens

When it is introduced

Applies to

How to prevent it

How to detect it

Fuzzing

Automated Dynamic Analysis

Code examples

Illustrative examples

Related weaknesses

Parent

Child

Terminology & mappings

Mapped taxonomies

Frequently asked questions

References

Stay ahead of CWE-763