High severity · published Mar 23, 2026
CVE-2026-25075
strongSwan 4.5.0 < 6.0.5 EAP-TTLS AVP Parsing Integer Underflow
7.5
CVSS
1.1%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.1% · higher than 64% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ST
strongSwan · strongSwan
4.5.0 before 6.0.5 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-25075
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-25075
www.strongswan.org
https://www.strongswan.org/blog/2026/03/23/strongswan-6.0.5-released.html
www.strongswan.org
https://www.strongswan.org/blog/2026/03/23/strongswan-vulnerability-(cve-2026-25075).html
www.vulncheck.com
https://www.vulncheck.com/advisories/strongswan-eap-ttls-avp-parsing-integer-underflow
y637f9qq2x.com
https://y637f9qq2x.com/posts/cve-2026-25075/
lists.debian.org
https://lists.debian.org/debian-lts-announce/2026/03/msg00016.html
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