ALAS2-2026-3800

Amazon Linux 2 Security Advisory: ALAS2-2026-3800
Advisory Released Date: 2026-07-20
Advisory Updated Date: 2026-07-20

Severity: Important

References: CVE-2026-56403 CVE-2026-56406 CVE-2026-56407
FAQs regarding Amazon Linux ALAS/CVE Severity

Issue Overview:

libexpat before 2.8.2 has an integer overflow in storeAtts. (CVE-2026-56403)

libexpat before 2.8.2 has an integer overflow in XML_ParseBuffer because it lacked a check that was present in XML_Parse. (CVE-2026-56406)

libexpat before 2.8.2 has an integer overflow in doProlog that is related to storeEntityValue and entity textLen. (CVE-2026-56407)

Affected Packages:

expat

Note:

This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.

Issue Correction:
Run yum update expat or yum update --advisory ALAS2-2026-3800 to update your system.

New Packages:

aarch64:
    expat-2.1.0-15.amzn2.0.8.aarch64
    expat-devel-2.1.0-15.amzn2.0.8.aarch64
    expat-static-2.1.0-15.amzn2.0.8.aarch64
    expat-debuginfo-2.1.0-15.amzn2.0.8.aarch64

i686:
    expat-2.1.0-15.amzn2.0.8.i686
    expat-devel-2.1.0-15.amzn2.0.8.i686
    expat-static-2.1.0-15.amzn2.0.8.i686
    expat-debuginfo-2.1.0-15.amzn2.0.8.i686

src:
    expat-2.1.0-15.amzn2.0.8.src

x86_64:
    expat-2.1.0-15.amzn2.0.8.x86_64
    expat-devel-2.1.0-15.amzn2.0.8.x86_64
    expat-static-2.1.0-15.amzn2.0.8.x86_64
    expat-debuginfo-2.1.0-15.amzn2.0.8.x86_64

Additional References

Release Notes: Amazon Linux 2 Release Notes

Red Hat: CVE-2026-56403, CVE-2026-56406, CVE-2026-56407

Mitre: CVE-2026-56403, CVE-2026-56406, CVE-2026-56407