Improper Handling of Unicode Encoding Affecting expat package, versions *


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.35% (29th percentile)

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  • Snyk IDSNYK-ECHOLATEST-EXPAT-19964094
  • published20 Sept 2026
  • disclosed19 Sept 2026

Introduced: 19 Sep 2026

NewCVE-2026-93990  (opens in a new tab)
CWE-176  (opens in a new tab)

How to fix?

There is no fixed version for Echo:latest expat.

NVD Description

Note: Versions mentioned in the description apply only to the upstream expat package and not the expat package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

Expat through 2.8.4 fails to validate low surrogates following high surrogates in UTF-16 input, allowing malformed UTF-16 sequences to be accepted. Attackers can craft UTF-16 encoded XML with lone high surrogates that consume following code units, hiding markup characters from the parser and enabling XML injection attacks.

CVSS Base Scores

version 3.1