CVE-2026-25210

libexpat: libexpat: Information disclosure and data integrity issues due to integer overflow in buffer reallocation

Published Jan 30, 2026 CVSS 3.1 · 6.9 Medium EPSS < 1% KEV · Not listed
Description
In libexpat before 2.7.4, the doContent function does not properly determine the buffer size bufSize because there is no integer overflow check for tag buffer reallocation.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4807-1 expat security update
Debian DSA Debian DSA DSA-6404-1 expat security update
Ubuntu USN Ubuntu USN USN-8022-1 Expat vulnerabilities
Ubuntu USN Ubuntu USN USN-8022-2 Expat vulnerabilities
Ubuntu USN Ubuntu USN USN-8023-1 xmltok library vulnerabilities
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 libexpat: libexpat: Information disclosure and data integrity issues due to integer overflow in buffer reallocation
References
Metrics threat_severity

None

threat_severity

Moderate

Type Values Removed Values Added
Description In libexpat before 2.7.4, the doContent function does not properly determine the buffer size bufSize because there is no integer overflow check for tag buffer reallocation.
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, 12:43 PM
Reserved
Jan 30, 2026, 6:40 AM
Status
Modified
Published
Jan 30, 2026, 7:16 AM
Modified
Nov 10, 2026, 1:18 PM
Severity
Moderate
Public date
Jan 30, 2026, 6:40 AM