Multiple high-severity denial-of-service vulnerabilities in libreswan (CVE-2026-50721, CVSS 8.1; CVE-2026-50722, CVSS 8.1; CVE-2026-12413, CVSS 7.5) can be triggered via crafted IKEv1/IKEv2 authentication payloads, malformed fragmentation, or badly formatted X.509 certificates. Affected versions are libreswan before 5.3.1, with CVE-2026-12413 specifically affecting versions 4.6 through 5.3. Users must upgrade to libreswan version 5.3.1 to remediate these issues.
Red Hat Product Errata RHSA-2026:46397 - Security Advisory Issued: 2026-07-27 Updated: 2026-07-27 RHSA-2026:46397 - Security Advisory Overview Updated Packages Synopsis Important: libreswan security update Type/Severity Security Advisory: Important Red Hat Lightspeed patch analysis Identify and remediate systems affected by this advisory. View affected systems Topic An update for libreswan is now available 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 for x86_64 9 x86_64 Red Hat Enterprise Linux for x86_64 - Extended Update Support 9.8 x86_64 Red Hat Enterprise Linux for IBM z Systems 9 s390x Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 9.8 s390x Red Hat Enterprise Linux for Power, little endian 9 ppc64le Red Hat Enterprise Linux for Power, little endian - Extended Update Support 9.8 ppc64le Red Hat Enterprise Linux for ARM 64 9 aarch64 Red Hat Enterprise Linux for ARM 64 - Extended Update Support 9.8 aarch64 Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.8 ppc64le Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.8 x86_64 Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.8 aarch64 Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.8 s390x Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.8 x86_64 Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.8 aarch64 Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.8 ppc64le Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.8 s390x 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 Note: More recent versions of these packages may be available. Click a package name for more details. Red Hat Enterprise Linux for x86_64 9 SRPM libreswan-4.15-10.el9_8.src.rpm SHA-256: 8627ece2d38ab60afe8d843af2057ce3c63977ca2c50be47abc00cfb8b9e6727 x86_64 libreswan-4.15-10.el9_8.x86_64.rpm SHA-256: 69aa4801f1891c48d07ed4a580359267ef34c8c0c254b4471c55b1511706a5f7 libreswan-debuginfo-4.15-10.el9_8.x86_64.rpm SHA-256: 40907591930df03c2225278c0b28526fccaf74683ebe69e3a5a1f2646fac64e7 libreswan-debugsource-4.15-10.el9_8.x86_64.rpm SHA-256: 1e06c5e8c3ae45dc069d8fb4dc900ca8e52895de015059618efb38e0ce1cc205 Red Hat Enterprise Linux for x86_64 - Extended Update Support 9.8 SRPM libreswan-4.15-10.el9_8.src.rpm SHA-256: 8627ece2d38ab60afe8d843af2057ce3c63977ca2c50be47abc00cfb8b9e6727 x86_64 libreswan-4.15-10.el9_8.x86_64.rpm SHA-256: 69aa4801f1891c48d07ed4a580359267ef34c8c0c254b4471c55b1511706a5f7 libreswan-debuginfo-4.15-10.el9_8.x86_64.rpm SHA-256: 40907591930df03c2225278c0b28526fccaf74683ebe69e3a5a1f2646fac64e7 libreswan-debugsource-4.15-10.el9_8.x86_64.rpm SHA-256: 1e06c5e8c3ae45dc069d8fb4dc900ca8e52895de015059618efb38e0ce1cc205 Red Hat Enterprise Linux for IBM z Systems 9 SRPM libreswan-4.15-10.el9_8.src.rpm SHA-256: 8627ece2d38ab60afe8d843af2057ce3c63977ca2c50be47abc00cfb8b9e6727 s390x libreswan-4.15-10.el9_8.s390x.rpm SHA-256: e6715f0fa0f53318ff733ca323c0dae93d12eed65f6190bdb8f4ab68bb857d3e libreswan-debuginfo-4.15-10.el9_8.s390x.rpm SHA-256: 1f070410df4833deef17e229f2ac6d2ad9722443d9211b32ec43929356b967c5 libreswan-debugsource-4.15-10.el9_8.s390x.rpm SHA-256: 99c7c5eb4b9c5e06a8be02a39107ef1dcc68e740e35675f5174bc0b57c7ac1b2 Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 9.8 SRPM libreswan-4.15-10.el9_8.src.rpm SHA-256: 8627ece2d38ab60afe8d843af2057ce3c63977ca2c50be47abc00cfb8b9e6727 s390x libreswan-4.15-10.el9_8.s390x.rpm SHA-256: e6715f0fa0f53318ff733ca323c0dae93d12eed65f6190bdb8f4ab68bb857d3e libreswan-debuginfo-4.15-10.el9_8.s390x.rpm SHA-256: 1f070410df4833deef17e229f2ac6d2ad9722443d9211b32ec43929356b967c5 libreswan-debugsource-4.15-10.el9_8.s390x.rpm SHA-256: 99c7c5eb4b9c5e06a8be02a39107ef1dcc68e740e35675f5174bc0b57c7ac1b2 Red Hat Enterprise Linux for Power, little endian 9 SRPM libreswan-4.15-10.el9_8.src.rpm SHA-256: 8627ece2d38ab60afe8d843af2057ce3c63977ca2c50be47abc00cfb8b9e6727 ppc64le libreswan-4.15-10.el9_8.ppc64le.rpm SHA-256: 4daa18072f58384ad27a92266c743b589c245ba27c314a72638a098916f533c6 libreswan-debuginfo-4.15-10.el9_8.ppc64le.rpm SHA-256: 336ba4daa7e8e48c28f572113a3e40c431037aa06b89b57669aabe9d5c538543 libreswan-debugsource-4.15-10.el9_8.ppc64le.rpm SHA-256: 2f4edc37d3ad85415583f2b76d3ae8f858100cf3f78403bd5cd33ebc1021d60c Red Hat Enterprise Linux for Power, little endian - Extended Update Support 9.8 SRPM libreswan-4.15-10.el9_8.src.rpm SHA-256: 8627ece2d38ab60afe8d843af2057ce3c63977ca2c50be47abc00cfb8b9e6727 ppc64le libreswan-4.15-10.el9_8.ppc64le.rpm SHA-256: 4daa18072f58384ad27a92266c743b589c245ba27c314a72638a098916f533c6 libreswan-debuginfo-4.15-10.el9_8.ppc64le.rpm SHA-256: 336ba4daa7e8e48c28f572113a3e40c431037aa06b89b57669aabe9d5c538543 libreswan-debugsource-4.15-10.el9_8.ppc64le.rpm SHA-256: 2f4edc37d3ad85415583f2b76d3ae8f858100cf3f78403bd5cd33ebc1021d60c Red Hat Enterprise Linux for ARM 64 9 SRPM libreswan-4.15-10.el9_8.src.rpm SHA-256: 8627ece2d38ab60afe8d843af2057ce3c63977ca2c50be47abc00cfb8b9e6727 aarch64 libreswan-4.15-10.el9_8.aarch64.rpm SHA-256: 9bbb3885cdfe711fa08b66fecbc825c581caae0f51db2102c4a8ed9b1d4b23a4 libreswan-debuginfo-4.15-10.el9_8.aarch64.rpm SHA-256: 7e5a23529869779295312960f0463afa849c356e10d46bc0b984993ffc9aa308 libreswan-debugsource-4.15-10.el9_8.aarch64.rpm SHA-256: 0a7abec6347629628cdd3e9849120cce30ccf028e7753dfbdacfc94bf762a5be Red Hat Enterprise Linux for ARM 64 - Extended Update Support 9.8 SRPM libreswan-4.15-10.el9_8.src.rpm SHA-256: 8627ece2d38ab60afe8d843af2057ce3c63977ca2c50be47abc00cfb8b9e6727 aarch64 libreswan-4.15-10.el9_8.aarch64.rpm SHA-256: 9bbb3885cdfe711fa08b66fecbc825c581caae0f51db2102c4a8ed9b1d4b23a4 libreswan-debuginfo-4.15-10.el9_8.aarch64.rpm SHA-256: 7e5a23529869779295312960f0463afa849c356e10d46bc0b984993ffc9aa308 libreswan-debugsource-4.15-10.el9_8.aarch64.rpm SHA-256: 0a7abec6347629628cdd3e9849120cce30ccf028e7753dfbdacfc94bf762a5be Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.8 SRPM libreswan-4.15-10.el9_8.src.rpm SHA-256: 8627ece2d38ab60afe8d843af2057ce3c63977ca2c50be47abc00cfb8b9e6727 ppc64le libreswan-4.15-10.el9_8.ppc64le.rpm SHA-256: 4daa18072f58384ad27a92266c743b589c245ba27c314a72638a098916f533c6 libreswan-debuginfo-4.15-10.el9_8.ppc64le.rpm SHA-256: 336ba4daa7e8e48c28f572113a3e40c431037aa06b89b57669aabe9d5c538543 libreswan-debugsource-4.15-10.el9_8.ppc64le.rpm SHA-256: 2f4edc37d3ad85415583f2b76d3ae8f858100cf3f78403bd5cd33ebc1021d60c Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.8 SRPM libreswan-4.15-10.el9_8.src.rpm SHA-256: 8627ece2d38ab60afe8d843af2057ce3c63977ca2c50be47abc00cfb8b9e6727 x86_64 libreswan-4.15-10.el9_8.x86_64.rpm SHA-256: 69aa4801f1891c48d07ed4a580359267ef34c8c0c254b4471c55b1511706a5f7 libreswan-debuginfo-4.15-10.el9_8.x86_64.rpm SHA-256: 40907591930df03c2225278c0b28526fccaf74683ebe69e3a5a1f2646fac64e7 libreswan-debugsource-4.15-10.el9_8.x86_64.rpm SHA-256: 1e06c5e8c3ae45dc069d8fb4dc900ca8e52895de015059618efb38e0ce1cc205 Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.8 SRPM libreswan-4.15-10.el9_8.src.rpm SHA-256: 8627ece2d38ab60afe8d843af2057ce3c63977ca2c50be47abc00cfb8b9e6727 aarch64 libreswan-4.15-10.el9_8.aarch64.rpm SHA-256: 9bbb3885cdfe711fa08b66fecbc825c581caae0f51db2102c4a8ed9b1d4b23a4 libreswan-debuginfo-4.15-10.el9_8.aarch64.rpm SHA-256: 7e5a23529869779295312960f0463afa849c356e10d46bc0b984993ffc9aa308 libreswan-debugsource-4.15-10.el9_8.aarch64.rpm SHA-256: 0a7abec6347629628cdd3e9849120cce30ccf028e7753dfbdacfc94bf762a5be Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.8 SRPM libreswan-4.15-10.el9_8.src.rpm SHA-256: 8627ece2d38ab60afe8d843af2057ce3c63977ca2c50be47abc00cfb8b9e6727 s390x libreswan-4.15-10.el9_8.s390x.rpm SHA-256: e6715f0fa0f53318ff733ca323c0dae93d12eed65f6190bdb8f4ab68bb857d3e libreswan-debuginfo-4.15-10.el9_8.s390x.rpm SHA-256: 1f070410df4833deef17e229f2ac6d2ad9722443d9211b32ec43929356b967c5 libreswan-debugsource-4.15-10.