Name: CVE-2026-56406: Integer Overflow or Wraparound
Creator: Rapid7
Published: 2026-06-21T00:00:00.000Z
License: https://www.rapid7.com/legal/website-terms-of-use/
Keywords: CVE, CVE-2026-56406, CWE-190, CVSS 6.9, EPSS 0.00174

libexpat before 2.8.2 has an integer overflow in XML_ParseBuffer because it lacked a check that was present in XML_Parse.

CVSS Details

CVSS 3.1 Base Score: 6.9
CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L)

Covered by Rapid7

Product	Vendor Advisory	Solution File	Added	Published
Alpine Linux	—	Upgrade expat	Jun 29, 2026	Jun 21, 2026
Amazon Linux Ami 2	—	Upgrade expat-develUpgrade thunderbirdUpgrade expatUpgrade firefoxUpgrade expat-debuginfoUpgrade expat-static	Jul 8, 2026	Jul 8, 2026
Amazon_linux_2023	—	Upgrade firefox-debuginfoUpgrade expat-debugsourceUpgrade firefoxUpgrade expat-debuginfoUpgrade expat-staticUpgrade firefox-debugsourceUpgrade expatUpgrade expat-devel	Jul 8, 2026	Jun 21, 2026
Debian	—	Upgrade expat	Aug 2, 2026	Aug 2, 2026
Freebsd	—	Upgrade expatUpgrade linux-rl9-expatUpgrade linux-c7-expat	Jun 30, 2026	Jun 28, 2026
Ibm Aix	—	Apply the fix or workaround for python_advisory20	Jul 15, 2026	Jul 14, 2026
Redhat_linux	—	No solution exists	Jul 17, 2026	Jun 21, 2026
Ubuntu	—	Upgrade libexpat1-devUpgrade libexpat1Upgrade expat (Ubuntu Pro)Upgrade lib64expat1-dev (Ubuntu Pro)Upgrade libexpat1-dev (Ubuntu Pro)Upgrade libexpat1 (Ubuntu Pro)Upgrade lib64expat1 (Ubuntu Pro)Upgrade expat	Sep 24, 2026	Jun 21, 2026

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CVSS Details

Covered by Rapid7

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