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.

🔗 CVE IDs covered (1)

🎯 Affected products4

• azl3 strongswan 5.9.14-7 on Azure Linux 3.0
• azl3 strongswan 5.9.14-8 on Azure Linux 3.0
• cbl2 strongswan 5.9.10-3 on CBL Mariner 2.0
• cbl2 strongswan 5.9.10-4 on CBL Mariner 2.0

✅ Remediation

KBCBL-Mariner Releases (Security Update) — fixed build 5.9.14-8 KBCBL-Mariner Releases (Security Update) — fixed build 5.9.10-4

🔗 References (2)

• advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-62291
• referencehttps://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade