CVE-2026-56412

medium

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.

References

https://github.com/hextheshadow/PoC-Exploit

https://github.com/libexpat/libexpat/pull/1278

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-38189

https://cert-portal.siemens.com/productcert/html/ssa-457936.html

Details

Source: Mitre, NVD

Published: 2026-06-21

Updated: 2026-11-10

Named Vulnerability: GHSA-m2mm-5w64-p8p7

Risk Information

CVSS v2

Base Score: 4.6

Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:P/A:P

Severity: Medium

CVSS v3

Base Score: 5.9

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

Severity: Medium

EPSS

EPSS: 0.00194