RHSA-2026:46986 - Security Advisory

Topic

An update for libreswan is now available for Fast Datapath for Red Hat Enterprise Linux 9.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

Libreswan is an implementation of IPsec and IKE for Linux. IPsec is the Internet Protocol Security and uses strong cryptography to provide both authentication and encryption services. These services allow you to build secure tunnels through untrusted networks such as virtual private network (VPN).

Security Fix(es):

• librenswan: IKEv1 Denial of Service via RSA-SHA1 (PKCS#1 Version 1.5 Encrypted) authentication payload (CVE-2026-50721)
• librenswan: IKEv2 Denial of Service via RSA-SHA1 (PKCS#1 RSASSA-PKCS1-v1_5) authentication payload (CVE-2026-50722)
• librenswan: IKEv2 Denial of Service via malformed fragmentation (CVE-2026-12413)
• libreswan: badly formatted X.509 certificate can cause an assertion failure that crashes the daemon process (CVE-2026-14957)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Fast Datapath 9 x86_64
• Red Hat Enterprise Linux Fast Datapath (for RHEL Server for IBM Power LE) 9 ppc64le
• Red Hat Enterprise Linux Fast Datapath (for IBM z Systems) 9 s390x
• Red Hat Enterprise Linux Fast Datapath (for RHEL for ARM 64) 9 aarch64

Fixes

• BZ - 2494147 - CVE-2026-50721 librenswan: IKEv1 Denial of Service via RSA-SHA1 (PKCS#1 Version 1.5 Encrypted) authentication payload
• BZ - 2494148 - CVE-2026-50722 librenswan: IKEv2 Denial of Service via RSA-SHA1 (PKCS#1 RSASSA-PKCS1-v1_5) authentication payload
• BZ - 2494149 - CVE-2026-12413 librenswan: IKEv2 Denial of Service via malformed fragmentation
• BZ - 2501764 - CVE-2026-14957 libreswan: badly formatted X.509 certificate can cause an assertion failure that crashes the daemon process

CVEs

• CVE-2026-12413
• CVE-2026-14957
• CVE-2026-50721
• CVE-2026-50722

References

• https://access.redhat.com/security/updates/classification/#important