CWE-173Variant

Improper Handling of Alternate Encoding

Draft in the CWE catalog · 8 CVEs mapped

8
CVEs mapped
4.4
Median CVSS
What it is

The product does not properly handle when an input uses an alternate encoding that is valid for the control sphere to which the input is being sent.

Recent examples
5.3cvss
CVE-2026-103276

CVE-2026-103276 - MEDIUM Severity Vulnerability

Ghost versions before 6.20.0 contain a file extension filtering bypass vulnerability that allows unauthenticated attackers to read theme templates and metadata. Attackers can use URL encoding to bypass extension validation and access sensitive theme files.

MEDIUMno explanation yet
0%
epss
—none
CVE-2026-81638

CVE-2026-81638 - UNKNOWN Severity Vulnerability

Improper Handling of Alternate Encoding vulnerability in ash-project ash_double_entry allows an attacker to submit several distinct string spellings of the same identifier. AshDoubleEntry.ULID renders a 128-bit ULID as 26 Crockford base-32 characters, but the first character encodes only 3 bits, so canonical values are 0 to 7. decode/1 in lib/ulid.ex masks the first character to its low 3 bits and valid?/1 accepts all 32 characters in that position, so 0..., 8..., G... and R... decode to the identical 16-byte value and resolve to the same row. When the type is exposed as a public ID over an HTTP or API boundary, an attacker-supplied ID can be spelled differently from the record it actually reads or writes, desynchronizing or bypassing string-level checks such as idempotency and deduplication keys, deny-lists, audit correlation, or signatures computed over the submitted ID. This issue affects ash_double_entry: from 0.1.0 before 1.0.19.

no explanation yet
0%
epss
7.4cvss
CVE-2026-19611

CVE-2026-19611 - HIGH Severity Vulnerability

A flaw was found in WildFly Elytron. Password hashing and verification normalize input with Unicode NFKC, which can collapse fullwidth characters to ASCII equivalents. A remote attacker can more easily guess affected passwords by using an ASCII-only dictionary against accounts whose passwords were intended to include those non-ASCII characters, leading to unauthorized access.

HIGHno explanation yet
1%
epss
The record
Technical detail
CWE ID
CWE-173
Abstraction
Variant
Structure
Simple
Status
Draft