Also known as: Integer underflow
The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.
This can happen in signed and unsigned cases.
244 recorded CVEs are caused by CWE-191 (Integer Underflow (Wrap or Wraparound)), including 1 in CISA's KEV (Known Exploited Vulnerabilities) catalog. KEVs are shown first. 44 new CWE-191 CVEs have been recorded so far in 2026 (62 in 2025).
Windows Remote Desktop Licensing Service Remote Code Execution Vulnerability
Showing 12 of 244 recorded CWE-191 CVEs. Track new ones as they are published and get AI-written analysis and fixes.
Monitor CWE-191 vulnerabilitiesWhat can happen when CWE-191 is exploited.
DoS: Crash, Exit, or Restart, DoS: Resource Consumption (CPU), DoS: Resource Consumption (Memory), DoS: Instability
Affects: Availability
This weakness will generally lead to undefined behavior and therefore crashes. In the case of overflows involving loop index variables, the likelihood of infinite loops is also high.
Modify Memory
Affects: Integrity
If the value in question is important to data (as opposed to flow), simple data corruption has occurred. Also, if the wrap around results in other conditions such as buffer overflows, further memory corruption may occur.
Execute Unauthorized Code or Commands, Bypass Protection Mechanism
Affects: Confidentiality, Availability, Access Control
This weakness can sometimes trigger buffer overflows which can be used to execute arbitrary code. This is usually outside the scope of a program's implicit security policy.
Typically introduced during these phases of the software lifecycle.
Languages
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.)
Effectiveness: High
Illustrative examples from MITRE showing how the weakness appears in code.
The following example subtracts from a 32 bit signed integer.
Vulnerable example
#include <stdio.h>The example has an integer underflow. The value of i is already at the lowest negative value possible, so after subtracting 1, the new value of i is 2147483647.
This code performs a stack allocation based on a length calculation.
Vulnerable example
int a = 5, b = 6;Real CVEs that MITRE cites as examples of this weakness.
Common questions about CWE-191.
The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.
244 recorded CVEs are attributed to CWE-191, including CVE-2014-0497, CVE-2022-1698, CVE-2026-37534. 1 are listed in CISA's Known Exploited Vulnerabilities (KEV) catalog.
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.)
Exploiting CWE-191 can lead to: DoS: Crash, Exit, or Restart, DoS: Resource Consumption (CPU), DoS: Resource Consumption (Memory), DoS: Instability, Modify Memory, Execute Unauthorized Code or Commands.
Yes. 1 CWE-191 vulnerabilities are in CISA's KEV catalog of actively exploited flaws, out of 244 recorded CVEs.
Weakness data is sourced from the MITRE CWE catalog (v4.20). CVE associations are aggregated and kept current by RadicalNotion.AI.
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