Disclosure summary
libexpat before 2.8.0 uses insufficient entropy, and thus hash flooding can occur via a crafted XML document.
Source-reported weakness categories
CWE-331
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
Microsoft Security Updates (CVRF) · 2026-Apr
Open original source · Updated Sep 24, 2026
libexpat before 2.8.0 uses insufficient entropy, and thus hash flooding can occur via a crafted XML document.
Maximum of vendor-reported product scores; products and fixed builds are associations, not a universal affected-version statement.
Microsoft maximum product score: 2.9
| Vendor | Product / association | Version / bounds |
|---|---|---|
| Microsoft update guide | cbl2 expat 2.6.4-4 on CBL Mariner 2.0 | (MSRC status code 3) |
| Microsoft update guide | cbl2 expat 2.6.4-4 on CBL-Mariner 2.0 | (MSRC status code 3) |
| Microsoft update guide | azl3 expat 2.6.4-5 on Azure Linux 3.0 | (MSRC status code 3) |
| Microsoft update guide | azl3 expat 2.6.4-6 on Azure Linux 3.0 | (MSRC status code 3) |
Vendor remediation references
- Release Notes · product IDs 20943-21692
- Vendor guidance · product IDs 20943-21692
- CBL-Mariner Releases · build 2.8.2-1 · product IDs 21279-17084
- Vendor guidance · product IDs 21279-17084
Original records & references
- NIST NVD record
- CVE Program record
- msrc.microsoft.com — Vendor advisory
PUBLISHED 2026-04-17T21:01:25-04:00
MODIFIED 2026-09-24T22:18:05-04:00
INGESTED 2026-10-08T12:45:03-04:00