CVE-2026-25075
strongSwan 4.5.0 < 6.0.5 EAP-TTLS AVP Parsing Integer Underflow
- Published
- Mar 23, 2026
- Updated
- Jul 14, 2026
- Assigning CNA
- VulnCheck
- Evidence observed
- Aug 20, 2026
Primary CVSS
nvd · CVSS 4.0
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XLow · next 30 days
- Percentile
- 61.2%
- Model date
- Sep 21, 2026
EPSS is a statistical estimate, not a certainty or a measure of impact. Combine it with CVSS, KEV status, exposure and your environment.
Summary
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.
Sources
1- CVE-2026-25075-checkScanner
Non-destructive vulnerability scanner for CVE-2026-25075 in strongSwan VPN servers. Detects integer underflow in EAP-TTLS plugin via crafted AVP without causing disruption.
Responsible use
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