CVE-2026-14957
Description
A flaw was found in Libreswan. An unauthenticated remote attacker can send a specially crafted X.509 certificate payload during an IKEv1 or IKEv2 exchange. This flaw occurs when Libreswan is operating in FIPS (Federal Information Processing Standards) mode and processing a certificate with an invalid public key, such as an RSA exponent of zero. This can trigger an assertion failure, leading to the termination of the daemon process and a denial of service.
Statement
Moderate: This flaw in Libreswan, when operating in FIPS mode with certificate-based authentication, allows an unauthenticated remote attacker to trigger a denial of service. The assertion failure occurs during X.509 certificate processing with a malformed certificate, leading to the daemon crashing.
This impact is limited to specific configurations where both FIPS mode and certificate-based authentication are actively utilized. It means, when Libreswan is running in FIPS mode and certificate-based authentication is in use with at least one CA certificate loaded in the Libreswan NSS database.
Deployments using only Pre-Shared Key (PSK) authentication without loaded CA certificates are not affected.
Mitigation
No mitigation is currently available that meets Red Hat Product Security's standards for usability, deployment, applicability, or stability. Customers are advised to apply the appropriate security updates once they become available.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker that can trigger an assert statement can still lead to a denial of service if the relevant code can be triggered by an attacker, and if the scope of the assert() extends beyond the attacker's own session.
Frequently Asked Questions
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