CVE-2025-59375: libexpat in Expat before 2.7.2 allows attackers to trigger large dynamic memory allocations via a small document that is submitted for parsing.

Overview

Severity
High (CVSS 7.5)
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U
Exploit Status
Not Exploited
Patch Tuesday
2025-Sep
Released
2025-09-16
EPSS Score
0.06% (percentile: 18.3%)

FAQ

Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability? One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.

Affected Products (8)

Open Source Software

  • cbl2 expat 2.6.4-2 on CBL Mariner 2.0
  • azl3 expat 2.6.4-2 on Azure Linux 3.0
  • cbl2 cmake 3.21.4-18 on CBL Mariner 2.0
  • cbl2 expat 2.6.4-1 on CBL Mariner 2.0
  • azl3 cmake 3.30.3-9 on Azure Linux 3.0
  • azl3 python3 3.12.9-4 on Azure Linux 3.0

Mariner

  • azl3 expat 2.6.4-1 on Azure Linux 3.0
  • cbl2 python3 3.9.19-14 on CBL Mariner 2.0

Revision History

  • 2025-09-16: Information published.