Vulnerability details
CVE-2026-77206
The Libreswan Project libreswan
IKEv2 pre-authentication Null Pointer Dereference in EAP code
CVSS 3.1
7.5High
Official description
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 scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 7.5High | 3.1 | CVEProject cvelistV5 (CNA) (libreswan) | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| The Libreswan Project | libreswan | 4.7 ≤ v ≤ 5.3.2 | CVEProject cvelistV5 (CNA) |
| The Libreswan Project | libreswan | 5.4 ≤ v ≤ 5.4 | CVEProject cvelistV5 (CNA) |
References and advisories
2
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Details
- Published
- 2026-10-14
- Last updated
- 2026-10-16
- State
- Published
- Assigner (CNA)
- libreswan
Exploit prediction (EPSS)
0.65%
Probability of exploitation in 30 days
51.7%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- Yes
- Exploitation
- None
- Technical impact
- Partial
Weaknesses (CWE)
- CWE-476Null Pointer Dereference