Description
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.
Published: 2026-03-23
Score: 8.7 High
EPSS: < 1% Very Low
KEV: No
Impact: Remote denial of service via integer underflow in EAP‑TTLS AVP parsing
Action: Immediate Patch
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4512-1 strongswan security update
Debian DSA Debian DSA DSA-6176-1 strongswan security update
History

Mon, 04 May 2026 19:00:00 +0000

Type Values Removed Values Added
References

Fri, 27 Mar 2026 20:30:00 +0000

Type Values Removed Values Added
References

Wed, 25 Mar 2026 15:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 24 Mar 2026 10:45:00 +0000

Type Values Removed Values Added
First Time appeared Strongswan
Strongswan strongswan
Vendors & Products Strongswan
Strongswan strongswan

Mon, 23 Mar 2026 19:30:00 +0000

Type Values Removed Values Added
Title strongSwan EAP-TTLS AVP Parsing Integer Underflow strongSwan 4.5.0 < 6.0.5 EAP-TTLS AVP Parsing Integer Underflow

Mon, 23 Mar 2026 19:00:00 +0000

Type Values Removed Values Added
Description 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.
Title strongSwan EAP-TTLS AVP Parsing Integer Underflow
Weaknesses CWE-191
CWE-476
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


Subscriptions

Strongswan Strongswan
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-05-06T14:41:06.076Z

Reserved: 2026-01-28T21:47:35.121Z

Link: CVE-2026-25075

cve-icon Vulnrichment

Updated: 2026-03-27T19:17:30.660Z

cve-icon NVD

Status : Deferred

Published: 2026-03-23T19:16:39.313

Modified: 2026-05-04T19:16:02.690

Link: CVE-2026-25075

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-03-25T20:37:13Z

Weaknesses