CVE-2026-25075

strongSwan 4.5.0 < 6.0.5 EAP-TTLS AVP Parsing Integer Underflow

HIGH
7.5
CVSS Score
Published: March 23, 2026 at 06:33 PM UTC
Updated: July 14, 2026 at 04:27 PM UTC
1 product affected across 1 vendorstrongSwan

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Severity
HIGH7.5
Exploit prediction
EPSS 1%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4.5.0 ≤ v < 6.0.54.5.0
Affected range stops below 6.0.5, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHVulnCheck
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-191CWE-476

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