CVE-2025-66382: expat looking for help with another unfixed non-public denial-of-service vulnerability [CVE-2025-66382]

Published Nov 28, 2025
·
Updated

In libexpat through 2.7.3, a crafted file with an approximate size of 2 MiB can lead to dozens of seconds of processing time.

Affected Software

5 affected componentsFixes available
Libexpat expat<2.7.3
Microsoft azl3 expat 2.6.4-2
Libexpat Project Libexpat<=2.7.3
Microsoft cbl2 expat 2.6.4-2
Microsoft azl3 expat 2.6.4-6<2.8.2-1
2.8.2-1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.8.2-1

Event History

Nov 28, 2025
CVE Published
via MITRE·12:00 AM
Data Sourced
via MITRE·12:00 AM
DescriptionSeverityWeakness
Data Sourced
via NVD·07:15 AM
DescriptionSeverityWeaknessAffected Software
Nov 29, 2025
Data Sourced
via Microsoft·01:01 AM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·01:01 AM
Affected Software
Updated
via Microsoft·09:01 AM
DescriptionSeverityWeakness
Updated
via Microsoft·09:01 AM
DescriptionSeverity
Updated
via Microsoft·09:01 AM
Affected Software

Frequently Asked Questions

1

What is the severity of CVE-2025-66382?

CVE-2025-66382 has a high severity as it can cause significant processing delays when handling specially crafted files.

2

How do I fix CVE-2025-66382?

To fix CVE-2025-66382, update libexpat to version 2.7.4 or later, which includes the necessary patches.

3

What impact does CVE-2025-66382 have on applications using libexpat?

CVE-2025-66382 can lead to performance degradation due to prolonged processing times when parsing large XML files.

4

Is CVE-2025-66382 a remote vulnerability?

CVE-2025-66382 is not remote; it requires an attacker to supply a specially crafted file to the vulnerable application.

5

Which versions of libexpat are affected by CVE-2025-66382?

CVE-2025-66382 affects all versions of libexpat up to and including 2.7.3.

Contact

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