CVE-2026-93990: Expat through 2.8.4 Malformed UTF-16 Acceptance via Unchecked Surrogate

Overview

Severity

High (CVSS 7.5)

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Exploit Status

Not Exploited

Patch Tuesday

2026-Sep

Released

2026-09-21

Last Updated

2026-09-21

EPSS Score

0.35% (percentile: 28.2%)

Affected Products (1)

Other

• 21887-17084

Security Updates (1)

• Security Update

Revision History

• 2026-09-21: Information published.
• 2026-09-21: Information published.