Description
libexpat before 2.8.4 lacks handler call depth tracking with custom encoding callbacks. Thus, a use-after-free can occur. NOTE: this is similar to CVE-2026-50219, CVE-2026-56131 and CVE-2026-56412.
Metrics
CVSS 3.1 7.8/10
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| libexpat project | libexpat | < 2.8.4 |
| 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/1322Issue Tracking, Patch, Vendor Advisory
- https://github.com/libexpat/libexpat/pull/1329Issue Tracking, Patch
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html
Timeline
- Published
- Aug 20, 2026
- Last modified
- Nov 10, 2026
- NVD status
- Modified