CVE-2025-62291 Integer overflow in strongSwan

High 8.1 Published Updated

A malicious EAP-MSCHAPv2 server can trigger an integer underflow leading to heap-based buffer overflow in strongSwan client, potentially allowing code execution or denial of service.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2025-62291?

CVE-2025-62291 is a high-severity vulnerability in strongSwan, published on 16 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-191

Which versions are affected by CVE-2025-62291?

Linux distribution packages (27)
strongswan SUSE:Enterprise Storage 7.1All versions5.8.2-150200.11.45.1
strongswan SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSAll versions5.8.2-150200.11.45.1
strongswan SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSAll versions5.9.11-150400.19.20.1
strongswan SUSE:Linux Enterprise High Performance Computing 15 SP4-LTSSAll versions5.9.11-150400.19.20.1
strongswan SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOSAll versions5.9.11-150500.5.9.1
strongswan SUSE:Linux Enterprise High Performance Computing 15 SP5-LTSSAll versions5.9.11-150500.5.9.1
strongswan SUSE:Linux Enterprise Module for Basesystem 15 SP6All versions5.9.12-150600.3.5.2
strongswan SUSE:Linux Enterprise Module for Basesystem 15 SP7All versions5.9.14-150700.3.3.1
strongswan SUSE:Linux Enterprise Module for Package Hub 15 SP6All versions5.9.12-150600.3.5.2
strongswan SUSE:Linux Enterprise Module for Package Hub 15 SP7All versions5.9.14-150700.3.3.1
strongswan SUSE:Linux Enterprise Server 12 SP5-LTSSAll versions5.1.3-26.29.1
strongswan SUSE:Linux Enterprise Server 15 SP3-LTSSAll versions5.8.2-150200.11.45.1
strongswan SUSE:Linux Enterprise Server 15 SP4-LTSSAll versions5.9.11-150400.19.20.1
strongswan SUSE:Linux Enterprise Server 15 SP5-LTSSAll versions5.9.11-150500.5.9.1
strongswan SUSE:Linux Enterprise Server 16.0All versions6.0.1-160000.3.1
strongswan SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5All versions5.1.3-26.29.1
strongswan SUSE:Linux Enterprise Server for SAP Applications 15 SP3All versions5.8.2-150200.11.45.1
strongswan SUSE:Linux Enterprise Server for SAP Applications 15 SP4All versions5.9.11-150400.19.20.1
strongswan SUSE:Linux Enterprise Server for SAP Applications 15 SP5All versions5.9.11-150500.5.9.1
strongswan SUSE:Linux Enterprise Server for SAP applications 16.0All versions6.0.1-160000.3.1
strongswan SUSE:Linux Enterprise Workstation Extension 15 SP6All versions5.9.12-150600.3.5.2
strongswan SUSE:Linux Enterprise Workstation Extension 15 SP7All versions5.9.14-150700.3.3.1
strongswan SUSE:Manager Proxy LTS 4.3All versions5.9.11-150400.19.20.1
strongswan SUSE:Manager Server LTS 4.3All versions5.9.11-150400.19.20.1
strongswan openSUSE:Leap 15.6All versions5.9.12-150600.3.5.2
strongswan openSUSE:Leap 16.0All versions6.0.1-160000.3.1
strongswan openSUSE:TumbleweedAll versions6.0.3-1.1

How do I fix CVE-2025-62291?

Upgrade to a fixed version.

Is CVE-2025-62291 being exploited?

There is no known exploitation of CVE-2025-62291 in the wild and no public exploit code.

Sources

Also known as ALPINE-CVE-2025-62291, AZL-74660, AZL-74766, DEBIAN-CVE-2025-62291, DLA-4359-1, DSA-6041-1 and 15 more.

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