The product calls a function, procedure, or routine, but the caller specifies an argument that is the wrong data type, which may lead to resultant weaknesses.
View on MITREThis weakness is most likely to occur in loosely typed languages, or in strongly typed languages in which the types of variable arguments cannot be enforced at compilation time, or where there is implicit casting.
No mitigation information available for this CWE.
Because this function call often produces incorrect behavior, it will usually be detected during testing or normal operation of the product.
No examples or observed CVEs available for this CWE.
Additional facts reviewed against primary or authoritative security sources.
Documented detection approaches include Other; recorded impacts include Quality Degradation; related weaknesses include CWE-628. Use these source-defined anchors to turn CWE-686 into implementation, review, and verification checks for the affected component.
CWE-686: Function Call With Incorrect Argument Type — MITRE CWEUse NIST SSDF practices to make prevention of CWE-686, Function Call With Incorrect Argument Type, an explicit development outcome. Translate the CWE definition into security requirements and design constraints, choose safer implementation patterns and toolchain checks, and define acceptance evidence before release. Feed every confirmed occurrence back into the requirements, design review, and coding rules so the same root cause is removed across the product rather than patched in one location.
NIST SP 800-218 Secure Software Development Framework — National Institute of Standards and TechnologyUse CISA's Known Exploited Vulnerabilities catalog to test whether a vulnerability mapped to CWE-686, Function Call With Incorrect Argument Type, has evidence of exploitation in the wild. Confirm the CVE-to-CWE root-cause mapping independently before attaching the example, then capture the affected product, required action, and remediation deadline. A missing KEV match is not evidence that the weakness is unexploited, and a KEV entry must not be generalized to every occurrence of this CWE.
Known Exploited Vulnerabilities Catalog — Cybersecurity and Infrastructure Security AgencyApply MITRE's full root-cause mapping guidance when using CWE-686, Function Call With Incorrect Argument Type. Separate weakness language from attacker prerequisites and technical impact, check the entry's abstraction and vulnerability-mapping notes, and prefer the most specific Base or Variant supported by the evidence. Record the rejected alternatives and require an independent review before the mapping is used for remediation trends or program metrics.
CVE to CWE Root Cause Mapping Guidance — MITRE CWEApply MITRE's root-cause mapping quick tips to CWE-686, Function Call With Incorrect Argument Type. Confirm the finding describes the causal weakness rather than an impact or attack pattern, compare the abstraction and mapping notes with plausible alternatives, and have a second reviewer challenge the selection. Preserve the evidence and reasoning so recurring defects can be measured against one consistent identifier.
CVE to CWE Root Cause Mapping Quick Tips — MITRE CWECWE-686: Function Call With Incorrect Argument Type is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product calls a function, procedure, or routine, but the caller specifies an argument that is the wrong data type, which may lead to resultant weaknesses. This weakness is most likely to occur in loosely typed languages, or in strongly typed languages in which the types of variable arguments cannot be enforced at compilation time, or where there is implicit casting.
If exploited, CWE-686 (Function Call With Incorrect Argument Type) it can compromise Other, leading to outcomes such as Quality Degradation.
CWE-686 can be detected using Other. Combining automated tooling with manual review typically yields the best coverage.
CWE-686 commonly affects Not Language-Specific. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.
A CWE (Common Weakness Enumeration) like CWE-686 describes a category of software weakness — the underlying flaw type. A CVE (Common Vulnerabilities and Exposures) identifies a specific, real-world vulnerability in a particular product. In short, a CWE is the kind of mistake, and a CVE is an instance of that mistake being found in software.