High [CVE-2026-14957] badly formatted X.509 certificate can cause an assertion failure that crashes the daemon process
This high-severity Red Hat Linux advisory covers CVE-2026-14957 affecting Fast Datapath for Red Hat Enterprise Linux 9, Red Hat Enterprise Linux 10.0 Extended Update Support, Red Hat Enterprise Linux 8.
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Summary
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.
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. Red Hat severity: Moderate — CVSS 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).
Weakness: CWE-617.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · high-confidence parse· fetched 5 days ago·verify at source
- libreswan-0:5.3.2-1.el9fdp
- libreswan-0:5.3.2-1.el10_2
- libreswan-0:5.2-1.el10_0.5
- libreswan-0:4.12-2.el8_10.6
- libreswan-0:4.15-10.el9_8
- libreswan-0:4.15-8.el9_6.1
- RHSA-2026:46986
- RHSA-2026:46398
- RHSA-2026:55449
- RHSA-2026:46396
- RHSA-2026:46397
- RHSA-2026:57741
Official advisory · high-confidence parse· fetched 5 days ago·verify at source
Mitigation checklist
- 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.
Official advisory · high-confidence parse· fetched 5 days ago·verify at source
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