Home/CWE/Improper Handling of URL Encoding (Hex Encoding)
Weakness

Improper Handling of URL Encoding (Hex Encoding)

CWE-177 · Variant · Draft

The product does not properly handle when all or part of an input has been URL encoded.

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Weakness Relationships

Where this weakness sits in the CWE hierarchy. Walk up to broader classes or down to more specific variants.
Parent of this (broader)
ChildOfCWE-172 · Encoding Error
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Attack Patterns (CAPEC)

4
How adversaries exploit this weakness, per MITRE CAPEC.
CAPEC-120Double Encoding
CAPEC-468Generic Cross-Browser Cross-Domain Theft
CAPEC-64Using Slashes and URL Encoding Combined to Bypass Validation Logic
CAPEC-72URL Encoding
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CVEs With This Weakness

10
CVEs tagged with this weakness.
CVECVE-2026-6414
CVECVE-2026-29045
CVECVE-2026-22037
CVECVE-2026-22031
CVECVE-2025-11990
CVECVE-2024-48866
CVECVE-2024-23983
CVECVE-2022-3854
CVECVE-2022-27780
CVECVE-2018-3718
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