CVE-2026-77206
Libreswan's IKEv2 state machine has a null pointer dereference bug in the EAP handling code for authentication.
Published Oct 13, 2026 · updated Oct 13, 2026
Libreswan's IKEv2 state machine has a null pointer dereference bug in the EAP handling code for authentication. As a result of inconsistency within the IKEv2 state machine code, this bug can be triggered by any IKEv2 connection, even if EAP is not configured at all. The error is caused by a fall-through where it incorrectly dereferences ike->sa.st_eap which is NULL. A malicious IKE_AUTH packet can trigger this bug, meaning the peer does not need to be authenticated. The bug results in a crash and restart of the pluto daemon. No remote code execution is possible. Continued exploitation can cause a denial of service.
Code
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No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Oct 13, 2026 · Catalog
Detected
Libreswan's IKEv2 state machine has a null pointer dereference bug in the EAP handling code for authentication. As a result of inconsistency within the IKEv2 state machine code, this bug can be triggered by any IKEv2 connection, even if EAP is not configured at all. The error is caused by a fall-through where it incorrectly dereferences ike->sa.st_eap which is NULL. A malicious IKE_AUTH packet can
Sources
- CVE.orgVulnerability recordCVE-2026-77206
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-77206
30-day exploitation probability 0.5%
first.org - NIST NVDVulnerability recordCVE-2026-77206
Libreswan's IKEv2 state machine has a null pointer dereference bug in the EAP handling code for authentication. As a result of inconsistency within the IKEv2 state machine code, this bug can be triggered by any IKEv2 connection, even if EAP is not configured at all. The error is
nvd.nist.gov