CVE-2026-77206IKEv2 pre-authentication Null Pointer Dereference in EAP code
Updated under an hour ago ()
Does this affect you?
It affects The Libreswan Project libreswan. Add what you run to find out whether that includes you.
EPSS puts the chance of exploitation in the next 30 days at 0.52%, higher than 43% of scored CVEs.
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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.
- CVSS
- 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-476
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- 0.52% (percentile 43)
- Assigned by
- libreswan
- NVD analysis
- Awaiting Analysis
- Record last updated
- Oct 16, 2026
- First seen by InfoSec Signals
- Oct 13, 2026
Affected products
The Libreswan Project libreswan libreswan_project:libreswan (from the name) | from 4.7 through 5.3.2; from 5.4 through 5.4; 5.3.3 not affected; 5.4.1 not affected | CNA record |
References
- https://libreswan.org/security/CVE-2026-77206/CVE-2026-77206.txtvendor-advisory
- https://libreswan.org/security/CVE-2026-77206/patch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.