RHSA-2026:57741: Important: libreswan security update
Important: libreswan security update
Other sources
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-v15) 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.
— Red Hat
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
redhat/libreswanto a version that resolves this vulnerability.Fixed in 4.15-8.el9_6.1 - Upgrade
Upgrade
redhat/libreswan-debuginfoto a version that resolves this vulnerability.Fixed in 4.15-8.el9_6.1 - Upgrade
Upgrade
redhat/libreswan-debugsourceto a version that resolves this vulnerability.Fixed in 4.15-8.el9_6.1 - Upgrade
Upgrade
redhat/libreswanto a version that resolves this vulnerability.Fixed in 4.15-8.el9_6.1.aa - Upgrade
Upgrade
redhat/libreswan-debuginfoto a version that resolves this vulnerability.Fixed in 4.15-8.el9_6.1.aa - Upgrade
Upgrade
redhat/libreswan-debugsourceto a version that resolves this vulnerability.Fixed in 4.15-8.el9_6.1.aa
Event History
Frequently Asked Questions
What is the practical impact of these issues?
The listed flaws are denial-of-service conditions. Malformed IKE authentication or fragmentation payloads can cause service disruption, and a badly formatted X.509 certificate can crash the daemon through an assertion failure.
Which protocol inputs are implicated?
The affected inputs include IKEv1 RSA-SHA1 PKCS#1 v1.5 encrypted authentication payloads, IKEv2 RSA-SHA1 RSASSA-PKCS1-v1_5 authentication payloads, malformed IKEv2 fragmentation, and badly formatted X.509 certificates.