In libexpat before 2.7.4, XML_ExternalEntityParserCreate does not copy unknown encoding handler user data.
https://www.cisa.gov/news-events/ics-advisories/icsa-26-188-05
https://www.cisa.gov/news-events/ics-advisories/icsa-26-155-04
https://github.com/libexpat/libexpat/pull/1131
https://cert-portal.siemens.com/productcert/html/ssa-253495.html
Source: Mitre, NVD
Published: 2026-01-23
Updated: 2026-06-02
Base Score: 1
Vector: CVSS2#AV:L/AC:H/Au:S/C:N/I:N/A:P
Severity: Low
Base Score: 2.5
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
EPSS: 0.00004