CVE-2026-56407

Integer Overflow in libexpat XML Parser

Published Jun 21, 2026 CVSS 3.1 · 6.9 Medium EPSS < 1% KEV · Not listed
Description
libexpat before 2.8.2 has an integer overflow in doProlog that is related to storeEntityValue and entity textLen.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4765-1 expat security update
Debian DSA Debian DSA DSA-6404-1 expat security update
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Integer Overflow in libexpat XML Parser
Type Values Removed Values Added
Description libexpat before 2.8.2 has an integer overflow in doProlog that is related to storeEntityValue and entity textLen.
First Time appeared Libexpat Project
Libexpat Project libexpat
Weaknesses CWE-190
CPEs cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*
Vendors & Products Libexpat Project
Libexpat Project libexpat
References
Metrics cvssV3_1

{'score': 6.9, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Nov 10, 2026, 12:48 PM
Reserved
Jun 21, 2026, 3:49 PM
Status
Modified
Published
Jun 21, 2026, 4:16 PM
Modified
Nov 10, 2026, 1:19 PM