CVE-2026-56412

MediumCVSS 5.9/10Last modified Nov 10, 2026

Description

libexpat before 2.8.2 does not consider XML_TOK_DATA_CHARS in doCdataSection and thus lacks handler call depth tracking for various calls from within handlers in cases of a policy violation. Thus, a use-after-free can occur. NOTE: this issue exists because of an incomplete fix for CVE-2026-50219.

Metrics

CVSS 3.1 5.9/10CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Weakness enumeration

CWE-416

Affected software

Vendor	Product	Versions
libexpat project	libexpat	< 2.8.2
Siemens	SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)	>= V3.1.7, < *
Siemens	SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)	>= V3.1.7, < *
Siemens	SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)	>= V3.1.7, < *
Siemens	SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)	>= V3.1.7, < *
Siemens	SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)	>= V3.1.7, < *

References

https://github.com/libexpat/libexpat/pull/1278Issue Tracking, Patch
https://cert-portal.siemens.com/productcert/html/ssa-457936.html

Timeline

Published: Jun 21, 2026
Last modified: Nov 10, 2026
NVD status: Modified

Related CVEs from 2026

CVE-2026-5641310.0Storage Concentrator (SC & SCVM) contains a command injection vulnerability in the ms_service.pl service, which listens on TCP port 9000 by CVE-2026-564147.2A vulnerability exists in H.View IP cameras certificate-related upload interfaces allow authenticated users to store arbitrary file content CVE-2026-5641510.0Storage Concentrator (SC & SCVM) contains a command injection vulnerability within the debug.pl script that is reachable without authenticat CVE-2026-564164.8In NLnet Labs Unbound up to and including version 1.25.1, when the validator builds the canonical RDATA form for an RRSIG-covered PX/RP/MINF CVE-2026-56427.3A vulnerability was determined in Cyber-III Student-Management-System up to 1a938fa61e9f735078e9b291d2e6215b4942af3f. This affects an unknow CVE-2026-564229.4Multiple MISP core controllers and model capture paths accepted client-controlled request fields such as primary keys (id) and ownership/sco CVE-2026-564238.8MISP Core contained broken access-control checks in the bulk deletion flows for Event Reports and Sharing Groups. The affected deleteSelecti CVE-2026-564248.8MISP core contained multiple broken access-control flaws where authorization checks were performed against the wrong entity, or where owners CVE-2026-564258.8The Azure Active Directory (AAD) authentication implementation contained multiple weaknesses in its OAuth 2.0 authorization flow that could CVE-2026-564288.1The SSH service on BSH ELP (Electronic Platform) modules contains a platform-specific vulnerability due to an improperly secured default con CVE-2026-56432.4A vulnerability was identified in Cyber-III Student-Management-System up to 1a938fa61e9f735078e9b291d2e6215b4942af3f. This impacts an unknow CVE-2026-564328.2Unintended proxy or intermediary ('confused deputy') in the MigTD signing for the Intel(R) TDX Migration Trust Domain (MigTD) within Ring 0: