CVE-2026-56407: libexpat before 2.8.2 has an integer overflow in doProlog that is related to storeEntityValue and entity textLen.

Overview

Severity

Medium (CVSS 6.9)

CVSS Vector

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

Exploit Status

Not Exploited

Patch Tuesday

2026-Jun

Released

2026-06-27

Last Updated

2026-07-03

EPSS Score

0.17% (percentile: 6.1%)

Affected Products (3)

Other

• 21379-17084
• 21279-17084
• 21119-17084

Revision History

• 2026-06-27: Information published.
• 2026-06-28: Information published.
• 2026-06-29: Information published.
• 2026-07-03: Information published.