CVE-2025-62291

Severity CVSS v4.0:

Pending analysis

Type:

CWE-191 Integer Underflow (Wrap or Wraparound)

Publication date:

16/01/2026

Last modified:

16/01/2026

Description

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.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 8.10 HIGH
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x

8.10

Severity 3.x

HIGH

References to Advisories, Solutions, and Tools

https://github.com/strongswan/strongswan/commits/master/src/libcharon/plugins/eap_mschapv2
https://github.com/strongswan/strongswan/releases
https://www.strongswan.org/blog/2025/10/27/strongswan-vulnerability-%28cve-2025-62291%29.html
https://lists.debian.org/debian-lts-announce/2025/11/msg00002.html