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VULNERABILITIES

CVE-2026-93990 Details

Description

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.

Metrics

CVSS 3.x Severity and Vector Strings:

CNA: [email protected]CVSS-B:7.5 HIGHVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

References to Advisories, Solutions, and Tools

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URLSource(s)Tag(s)
https://github.com/libexpat/libexpat [email protected]
https://github.com/libexpat/libexpat/commit/ff6e1d7e750bbe245178f51a47a965dc8342861a [email protected]
https://github.com/libexpat/libexpat/pull/1282 [email protected]
https://www.vulncheck.com/advisories/expat-through-2.8.4-malformed-utf-16-acceptance-via-unchecked-surrogate [email protected]

Weakness Enumeration

CWE-IDCWE NameSource
CWE-176Improper Handling of Unicode Encoding[email protected]

Affected Products

No affected product data is available for this CVE.

Change History

2 change records found show changes

QUICK INFO

CVE Dictionary Entry:
CVE-2026-93990
NVD Published Date:
Sep 19, 2026
NVD Last Modified:
Sep 22, 2026
Source:
[email protected]
CVE-2026-93990 Details - Not Deferred