CWE-166 3 CVEs MITRE definition ↗

CWE-166: Improper Handling of Missing Special Element

Overview

CWE-166 (Improper Handling of Missing Special Element) documents a weakness type used across vulnerability databases and security assessments. Use the sections below for definition, context, and mapped CVEs.

Security impact
Security impact: Depends on product and context; use CVE records, severity scores, and MITRE guidance to prioritize.

Description

The product receives input from an upstream component, but it does not handle or incorrectly handles when an expected special element is missing.

Applicable platforms

Kind Name Class Prevalence OS / CPE
language Not Language-Specific Undetermined

Related CVEs in this database

These CVEs are mapped to this weakness in this database and kept for traceability and search.

CVE Published Summary
CVE-2026-32792 2026-05-20 NLnet Labs Unbound 1.6.2 up to and including version 1.25.0 has a denial of service vulnerability when compiled with DNSCrypt support ('--enable-dnscrypt'). A bad DNSCrypt query could underflow Unboun…
CVE-2026-21218 2026-02-10 Improper handling of missing special element in .NET allows an unauthorized attacker to perform spoofing over a network.
CVE-2024-38091 2024-07-09 Microsoft WS-Discovery Denial of Service Vulnerability

Previous names

  • Missing Special Element (2008-04-11)
  • Failure to Handle Missing Special Element (2009-05-27)

Content submission

Name
PLOVER
Date
2006-07-19
Version
Draft 3

Content modifications

Date Name Version Importance Comment
2008-07-01 Eric Dalci 1.0 updated Potential_Mitigations, Time_of_Introduction
2008-09-08 CWE Content Team 1.0 updated Relationships, Other_Notes, Taxonomy_Mappings
2009-03-10 CWE Content Team 1.3 updated Relationships
2009-05-27 CWE Content Team 1.4 updated Description, Name
2009-07-27 CWE Content Team 1.5 updated Potential_Mitigations
2009-10-29 CWE Content Team 1.6 updated Other_Notes
2011-03-29 CWE Content Team 1.12 updated Potential_Mitigations
2011-06-01 CWE Content Team 1.13 updated Common_Consequences
2012-05-11 CWE Content Team 2.2 updated Relationships
2012-10-30 CWE Content Team 2.3 updated Potential_Mitigations
2014-07-30 CWE Content Team 2.8 updated Relationships
2017-05-03 CWE Content Team 2.11 updated Potential_Mitigations
2017-11-08 CWE Content Team 3.0 updated Applicable_Platforms
2020-02-24 CWE Content Team 4.0 updated Potential_Mitigations, Relationships
2020-06-25 CWE Content Team 4.1 updated Potential_Mitigations
2023-01-31 CWE Content Team 4.10 updated Description, Potential_Mitigations
2023-04-27 CWE Content Team 4.11 updated Relationships
2023-06-29 CWE Content Team 4.12 updated Mapping_Notes
2024-02-29 CWE Content Team 4.14 updated Relationships
2025-12-11 CWE Content Team 4.19 updated Weakness_Ordinalities
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