CVE-2026-117610

libexpat through 2.9.0 NULL Pointer Dereference via External Entity Subparser

Published Oct 28, 2026 CVSS 4.0 · 8.2 High EPSS < 1% KEV · Not listed
Description
libexpat through 2.9.0 contains a NULL pointer dereference vulnerability in externalEntityInitProcessor2() in lib/xmlparse.c that mishandles the XML_TOK_NONE token from empty input. Attackers who control stream chunking can force an empty non-final first parse on an external entity subparser, causing a later parse to crash the application.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
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 through 2.9.0 contains a NULL pointer dereference vulnerability in externalEntityInitProcessor2() in lib/xmlparse.c that mishandles the XML_TOK_NONE token from empty input. Attackers who control stream chunking can force an empty non-final first parse on an external entity subparser, causing a later parse to crash the application.
Title libexpat through 2.9.0 NULL Pointer Dereference via External Entity Subparser
First Time appeared Libexpat Project
Libexpat Project libexpat
Weaknesses CWE-476
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:L/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 5, 2026, 3:47 PM
Reserved
Oct 27, 2026, 1:04 PM
Status
Analyzed
Published
Oct 28, 2026, 3:17 AM
Modified
Nov 5, 2026, 4:17 PM
Severity
Moderate
Public date
Oct 28, 2026, 2:03 AM