Summaryinfo

A vulnerability described as problematic has been identified in strongSwan up to 6.0.4. This affects an unknown part of the component TTLS AVP Parser. Such manipulation of the argument length leads to integer underflow. This vulnerability is traded as CVE-2026-25075. The attack may be launched remotely. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in strongSwan up to 6.0.4. It has been rated as problematic. Affected by this issue is an unknown code block of the component TTLS AVP Parser. The manipulation of the argument length with an unknown input leads to a integer underflow vulnerability. Using CWE to declare the problem leads to CWE-191. The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result. Impacted is availability. CVE summarizes:

strongSwan versions 4.5.0 prior to 6.0.5 contain an integer underflow vulnerability in the EAP-TTLS AVP parser that allows unauthenticated remote attackers to cause a denial of service by sending crafted AVP data with invalid length fields during IKEv2 authentication. Attackers can exploit the failure to validate AVP length fields before subtraction to trigger excessive memory allocation or NULL pointer dereference, crashing the charon IKE daemon.

The weakness was shared by Kazuma Matsumoto. The advisory is available at strongswan.org. This vulnerability is handled as CVE-2026-25075 since 01/28/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 303377 (Linux Distros Unpatched Vulnerability : CVE-2026-25075), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.0.5 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (303377) and EUVD (EUVD-2026-14477). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Network Encryption Software

Name

• strongSwan

Version

• 6.0.0
• 6.0.1
• 6.0.2
• 6.0.3
• 6.0.4

License

• open-source

CPE 2.3info

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CPE 2.2info

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