CVE-2026-56412

Public on 2026-06-21

Modified on 2026-06-23

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.

Severity

Medium

See what this means

CVSS v3 Base Score

5.6

See breakdown

Affected Packages

Platform	Package	Status
Amazon Linux 2 - Core	expat	Pending Fix
Amazon Linux 2023	expat	Pending Fix
Amazon Linux 2 - Firefox Extra	firefox	Pending Fix
Amazon Linux 2023	firefox	Pending Fix
Amazon Linux 2 - Core	thunderbird	Pending Fix
Amazon Linux 2023	xmlrpc-c	Not Affected

CVSS Scores

	Score Type	Score	Vector
Amazon Linux	CVSSv3	5.6	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L

References

FAQs regarding Amazon Linux ALAS/CVE Severity Red Hat: CVE-2026-56412 Mitre: CVE-2026-56412