The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.

While assertion is good for catching logic errors and reducing the chances of reaching more serious vulnerability conditions, it can still lead to a denial of service.
For example, if a server handles multiple simultaneous connections, and an assert() occurs in one single connection that causes all other connections to be dropped, this is a reachable assertion that leads to a denial of service.

Resultant

assertion failure

Implementation

Availability
DoS: Crash, Exit, or Restart
An attacker that can trigger an assert statement can still lead to a denial of service if the relevant code can be triggered by an attacker, and if the scope of the assert() extends beyond the attacker's own session.

Automated Static Analysis
Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
High

Implementation
Make sensitive open/close operation non reachable by directly user-controlled data (e.g. open/close resources)

Implementation
Input Validation
Perform input validation on user data.

In the excerpt below, an AssertionError (an unchecked exception) is thrown if the user hasn't entered an email address in an HTML form.

String email = request.getParameter("email_address");assert email != null;

CVE-2024-8768
API server for LLM library can crash when provided an empty prompt, which triggers a reachable assertion
https://www.cve.org/CVERecord?id=CVE-2024-8768

CVE-2023-49286
Chain: function in web caching proxy does not correctly check a return value (CWE-253) leading to a reachable assertion (CWE-617)
https://www.cve.org/CVERecord?id=CVE-2023-49286

CVE-2006-6767
FTP server allows remote attackers to cause a denial of service (daemon abort) via crafted commands which trigger an assertion failure.
https://www.cve.org/CVERecord?id=CVE-2006-6767

CVE-2006-6811
Chat client allows remote attackers to cause a denial of service (crash) via a long message string when connecting to a server, which causes an assertion failure.
https://www.cve.org/CVERecord?id=CVE-2006-6811

CVE-2006-5779
Product allows remote attackers to cause a denial of service (daemon crash) via LDAP BIND requests with long authcid names, which triggers an assertion failure.
https://www.cve.org/CVERecord?id=CVE-2006-5779

CVE-2006-4095
Product allows remote attackers to cause a denial of service (crash) via certain queries, which cause an assertion failure.
https://www.cve.org/CVERecord?id=CVE-2006-4095

CVE-2006-4574
Chain: security monitoring product has an off-by-one error that leads to unexpected length values, triggering an assertion.
https://www.cve.org/CVERecord?id=CVE-2006-4574

CVE-2004-0270
Anti-virus product has assert error when line length is non-numeric.
https://www.cve.org/CVERecord?id=CVE-2004-0270

MET01-J
Never use assertions to validate method arguments

SFP3
Use of an improper API

Allowed
This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.

CWE Content Team
MITRE
2007-05-07
Draft 6
2007-05-07

Sean Eidemiller
Cigital
2008-07-01
added/updated demonstrative examples

Eric Dalci
Cigital
2008-07-01
updated Potential_Mitigations, Time_of_Introduction

CWE Content Team
MITRE
2008-09-08
updated Description, Relationships, Observed_Example, Other_Notes, Weakness_Ordinalities

CWE Content Team
MITRE
2011-06-01
updated Common_Consequences

CWE Content Team
MITRE
2012-05-11
updated Common_Consequences, Observed_Examples, Relationships, Taxonomy_Mappings

CWE Content Team
MITRE
2012-10-30
updated Potential_Mitigations

CWE Content Team
MITRE
2014-06-23
updated Common_Consequences, Description, Other_Notes

CWE Content Team
MITRE
2014-07-30
updated Relationships, Taxonomy_Mappings

CWE Content Team
MITRE
2017-01-19
updated Relationships

CWE Content Team
MITRE
2017-11-08
updated Relationships

CWE Content Team
MITRE
2019-01-03
updated Relationships, Taxonomy_Mappings

CWE Content Team
MITRE
2019-06-20
updated Relationships, Type

CWE Content Team
MITRE
2019-09-19
updated Alternate_Terms

CWE Content Team
MITRE
2023-04-27
updated Detection_Factors, Relationships

CWE Content Team
MITRE
2023-06-29
updated Mapping_Notes

CWE Content Team
MITRE
2023-10-26
updated Demonstrative_Examples

CWE Content Team
MITRE
2024-02-29
4.14
2024-02-29
updated Observed_Examples

CWE Content Team
MITRE
2025-12-11
4.19
2025-12-11
updated Applicable_Platforms, Observed_Examples, Relationships