CVE-2026-102633

libexpat 2.7.2 through 2.8.5 Integer Overflow in expat_realloc

Published Sep 29, 2026 CVSS 4.0 · 8.2 High EPSS < 1% KEV · Not listed
Description
libexpat versions 2.7.2 through 2.8.5 contain an integer overflow vulnerability in expat_realloc() function on 32-bit platforms when computing allocation sizes. Attackers supplying malicious XML to applications parsing with vulnerable libexpat can cause heap buffer overflow, memory corruption, or denial of service.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4849-1 expat security update
Debian DSA Debian DSA DSA-6566-1 expat security update
History
Type Values Removed Values Added
First Time appeared Libexpat
Libexpat expat
Vendors & Products Libexpat
Libexpat expat
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
Description libexpat versions 2.7.2 through 2.8.5 contain an integer overflow vulnerability in expat_realloc() function on 32-bit platforms when computing allocation sizes. Attackers supplying malicious XML to applications parsing with vulnerable libexpat can cause heap buffer overflow, memory corruption, or denial of service.
Title libexpat 2.7.2 through 2.8.5 Integer Overflow in expat_realloc
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': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.2, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Nov 10, 2026, 12:49 PM
Reserved
Sep 29, 2026, 3:50 PM
Status
Awaiting Analysis
Published
Sep 29, 2026, 5:17 PM
Modified
Nov 10, 2026, 1:18 PM
Severity
Moderate
Public date
Sep 29, 2026, 4:04 PM