CVE-2026-25075

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.

CVSS v4.0

8.7 HIGHCVSS: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:X

CVSS v3.1

7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

1.01% chance of exploitation in the next 30 days, 61th percentile

Published

2026-03-23

Updated

2026-07-14

Proof-of-concept exploits (2)

• https://www.strongswan.org/blog/2026/03/23/strongswan-vulnerability-(cve-2026-25075).html
• https://y637f9qq2x.com/posts/cve-2026-25075/

References

• CVE Record
• NVD entry

Related

• CVE-2026-25069
• CVE-2026-25089
• CVE-2026-25059
• CVE-2026-25099
• CVE-2026-25053
• CVE-2026-25119