Disclosure summary
In the eap-mschapv2 plugin (client-side) in strongSwan before 6.0.3, a malicious EAP-MSCHAPv2 server can send a crafted message of size 6 through 8, and cause an integer underflow that potentially results in a heap-based buffer overflow.
Source-reported weakness categories
CWE-191
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-Jan
Open original source · Updated Feb 18, 2026
In the eap-mschapv2 plugin (client-side) in strongSwan before 6.0.3, a malicious EAP-MSCHAPv2 server can send a crafted message of size 6 through 8, and cause an integer underflow that potentially results in a heap-based buffer overflow.
Maximum of vendor-reported product scores; products and fixed builds are associations, not a universal affected-version statement.
Microsoft maximum product score: 8.1
| Vendor | Product / association | Version / bounds |
|---|---|---|
| Microsoft update guide | azl3 strongswan 5.9.14-7 on Azure Linux 3.0 | (MSRC status code 3) |
| Microsoft update guide | cbl2 strongswan 5.9.10-3 on CBL Mariner 2.0 | (MSRC status code 3) |
| Microsoft update guide | azl3 strongswan 5.9.14-8 on Azure Linux 3.0 | (MSRC status code 3) |
| Microsoft update guide | cbl2 strongswan 5.9.10-4 on CBL Mariner 2.0 | (MSRC status code 3) |
Vendor remediation references
- CBL-Mariner Releases · build 5.9.14-8 · product IDs 20818-17084, 20896-17084
- Vendor guidance · product IDs 20818-17084, 20896-17084
- CBL-Mariner Releases · build 5.9.10-4 · product IDs 18241-17086, 20897-17086
- Vendor guidance · product IDs 18241-17086, 20897-17086
Original records & references
- NIST NVD record
- CVE Program record
- msrc.microsoft.com — Vendor advisory
PUBLISHED 2026-01-17T20:01:53-05:00
MODIFIED 2026-02-18T09:53:23-05:00
INGESTED 2026-10-08T12:45:20-04:00