The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.

What CVEs are caused by CWE-835?

361 recorded CVEs are attributed to CWE-835, including CVE-2024-20353, CVE-2026-24816, CVE-2025-21850. 1 are listed in CISA's Known Exploited Vulnerabilities (KEV) catalog.

Is CWE-835 actively exploited?

Yes. 1 CWE-835 vulnerabilities are in CISA's KEV catalog of actively exploited flaws, out of 361 recorded CVEs.

CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')

Overview

CWE-835 (Loop with Unreachable Exit Condition ('Infinite Loop')) is a base-level software weakness catalogued by MITRE in the Common Weakness Enumeration (CWE). It describes a recurring type of mistake that can lead to exploitable security vulnerabilities.

Real-world CVEs

361 recorded CVEs are caused by CWE-835 (Loop with Unreachable Exit Condition ('Infinite Loop')), including 1 in CISA's KEV (Known Exploited Vulnerabilities) catalog. KEVs are shown first. 135 new CWE-835 CVEs have been recorded so far in 2026 (47 in 2025).

Showing 12 of 361 recorded CWE-835 CVEs. Track new ones as they are published and get AI-written analysis and fixes.

Monitor CWE-835 vulnerabilities

Common consequences

What can happen when CWE-835 is exploited.

DoS: Resource Consumption (CPU), DoS: Resource Consumption (Memory), DoS: Amplification

Affects: Availability

An infinite loop will cause unexpected consumption of resources, such as CPU cycles or memory. The software's operation may slow down, or cause a long time to respond.

How it happens

When it is introduced

Typically introduced during these phases of the software lifecycle.

Implementation

How to detect it

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.)

Effectiveness: High

Code examples

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

In the following code the method processMessagesFromServer attempts to establish a connection to a server and read and process messages from the server. The method uses a do/while loop to continue trying to establish the connection to the server when an attempt fails.

Vulnerable example

c

int processMessagesFromServer(char *hostaddr, int port) {

Safe example

c

int processMessagesFromServer(char *hostaddr, int port) {

However, this will create an infinite loop if the server does not respond. This infinite loop will consume system resources and can be used to create a denial of service attack. To resolve this a counter should be used to limit the number of attempts to establish a connection to the server, as in the following code.

For this example, the method isReorderNeeded is part of a bookstore application that determines if a particular book needs to be reordered based on the current inventory count and the rate at which the book is being sold.

Vulnerable example

java

public boolean isReorderNeeded(String bookISBN, int rateSold) {

Safe example

java

public boolean isReorderNeeded(String bookISBN, int rateSold) {

However, the while loop will become an infinite loop if the rateSold input parameter has a value of zero since the inventoryCount will never fall below the minimumCount. In this case the input parameter should be validated to ensure that a value of zero does not cause an infinite loop, as in the following code.

Illustrative examples

Real CVEs that MITRE cites as examples of this weakness.

CVE-2025-32399 — Chain: library for implementing Profinet devices does not check an input for a loop condition (CWE-606), allowing an infinite loop (CWE-835) via a crafted RPC packet
CVE-2022-22224 — Chain: an operating system does not properly process malformed Open Shortest Path First (OSPF) Type/Length/Value Identifiers (TLV) (CWE-703), which can cause the process to enter an infinite loop (CWE-835)
CVE-2022-25304 — A Python machine communication platform did not account for receiving a malformed packet with a null size, causing the receiving function to never update the message buffer and be caught in an infinite loop.
CVE-2011-1027 — Chain: off-by-one error (CWE-193) leads to infinite loop (CWE-835) using invalid hex-encoded characters.
CVE-2011-1142 — Chain: self-referential values in recursive definitions lead to infinite loop.
CVE-2011-1002 — NULL UDP packet is never cleared from a queue, leading to infinite loop.
CVE-2006-6499 — Chain: web browser crashes due to infinite loop - "bad looping logic [that relies on] floating point math [CWE-1339] to exit the loop [CWE-835]"
CVE-2010-4476 — Floating point conversion routine cycles back and forth between two different values.
CVE-2010-4645 — Floating point conversion routine cycles back and forth between two different values.
CVE-2010-2534 — Chain: improperly clearing a pointer in a linked list leads to infinite loop.
CVE-2013-1591 — Chain: an integer overflow (CWE-190) in the image size calculation causes an infinite loop (CWE-835) which sequentially allocates buffers without limits (CWE-1325) until the stack is full.
CVE-2008-3688 — Chain: A denial of service may be caused by an uninitialized variable (CWE-457) allowing an infinite loop (CWE-835) resulting from a connection to an unresponsive server.

How this weakness relates to others in the CWE hierarchy.

Parent

CWE-834: Excessive Iteration

Terminology & mappings

Mapped taxonomies

OMG ASCSM (ASCSM-CWE-835)

Frequently asked questions

Common questions about CWE-835.

What is CWE-835?: The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.
What CVEs are caused by CWE-835?: 361 recorded CVEs are attributed to CWE-835, including CVE-2024-20353, CVE-2026-24816, CVE-2025-21850. 1 are listed in CISA's Known Exploited Vulnerabilities (KEV) catalog.
How is CWE-835 detected?: 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.)
What are the consequences of CWE-835?: Exploiting CWE-835 can lead to: DoS: Resource Consumption (CPU), DoS: Resource Consumption (Memory), DoS: Amplification.
Is CWE-835 actively exploited?: Yes. 1 CWE-835 vulnerabilities are in CISA's KEV catalog of actively exploited flaws, out of 361 recorded CVEs.

References

Weakness data is sourced from the MITRE CWE catalog (v4.20). CVE associations are aggregated and kept current by RadicalNotion.AI.