Multiple denial-of-service vulnerabilities in libreswan's IKEv1 and IKEv2 implementations (CVE-2026-50721, CVSS 8.1; CVE-2026-50722, CVSS 8.1; CVE-2026-12413, CVSS 7.5) can be triggered via specially crafted RSA-SHA1 authentication payloads or malformed fragmentation. Affected versions are libreswan prior to version 5.3.1, with CVE-2026-12413 specifically affecting versions 4.6 through 5.3. The fix is to upgrade libreswan to version 5.3.1.
Red Hat Product Errata RHSA-2026:61779 - Security Advisory Issued: 2026-08-31 Updated: 2026-08-31 RHSA-2026:61779 - 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 9.2 Update Services for SAP Solutions. 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 Server - AUS 9.2 x86_64 Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.2 ppc64le Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.2 x86_64 Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.2 aarch64 Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.2 s390x Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.2 x86_64 Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.2 aarch64 Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.2 ppc64le Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.2 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 Server - AUS 9.2 SRPM libreswan-4.9-5.el9_2.5.src.rpm SHA-256: 1a81869e3a7210379c07292e149813406c303331e37fb20eb36ce4b0fd907e34 x86_64 libreswan-4.9-5.el9_2.5.x86_64.rpm SHA-256: 9bb70f6883c528222a8d49965fd709c46a60dc5d18387ff725aa8b16f48d46f6 libreswan-debuginfo-4.9-5.el9_2.5.x86_64.rpm SHA-256: 81db9a8d4fbe96afbedf31bce5933ccaaabc7013037b97a23bf04861909e05b8 libreswan-debugsource-4.9-5.el9_2.5.x86_64.rpm SHA-256: 4384188d0ccc497565560a3aff3d4e06e7f1b9d30f7b66cd21735ccfa3e2b403 Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.2 SRPM libreswan-4.9-5.el9_2.5.src.rpm SHA-256: 1a81869e3a7210379c07292e149813406c303331e37fb20eb36ce4b0fd907e34 ppc64le libreswan-4.9-5.el9_2.5.ppc64le.rpm SHA-256: c216a37bfb960934ca3265d323e73de9900d13a00a997f70a3924e9dc99486fa libreswan-debuginfo-4.9-5.el9_2.5.ppc64le.rpm SHA-256: e06bb3ad2f92c16eaf4345b037e4b1ca8a8f96a7e2c31e28596ffd38b3f4ee4d libreswan-debugsource-4.9-5.el9_2.5.ppc64le.rpm SHA-256: c2d857f3b6f096dcc2d2eb09d293e4ce71e42efb16844c2c81af09d4f024b10c Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.2 SRPM libreswan-4.9-5.el9_2.5.src.rpm SHA-256: 1a81869e3a7210379c07292e149813406c303331e37fb20eb36ce4b0fd907e34 x86_64 libreswan-4.9-5.el9_2.5.x86_64.rpm SHA-256: 9bb70f6883c528222a8d49965fd709c46a60dc5d18387ff725aa8b16f48d46f6 libreswan-debuginfo-4.9-5.el9_2.5.x86_64.rpm SHA-256: 81db9a8d4fbe96afbedf31bce5933ccaaabc7013037b97a23bf04861909e05b8 libreswan-debugsource-4.9-5.el9_2.5.x86_64.rpm SHA-256: 4384188d0ccc497565560a3aff3d4e06e7f1b9d30f7b66cd21735ccfa3e2b403 Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.2 SRPM libreswan-4.9-5.el9_2.5.src.rpm SHA-256: 1a81869e3a7210379c07292e149813406c303331e37fb20eb36ce4b0fd907e34 aarch64 libreswan-4.9-5.el9_2.5.aarch64.rpm SHA-256: 4a039cef627af6fb29f1c8b3f6cf7a2a92e56a838e4e5ada7677dea5c4c8f688 libreswan-debuginfo-4.9-5.el9_2.5.aarch64.rpm SHA-256: 5b8c1960ce1d1f4c1558a8ee35baf8319080d3e935f628b1a859e5867d55a2c7 libreswan-debugsource-4.9-5.el9_2.5.aarch64.rpm SHA-256: 3db2ed8e19b3d28ce0da1ab28a0641f9d9bf3682d1138366e9f07bd9a17c6575 Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.2 SRPM libreswan-4.9-5.el9_2.5.src.rpm SHA-256: 1a81869e3a7210379c07292e149813406c303331e37fb20eb36ce4b0fd907e34 s390x libreswan-4.9-5.el9_2.5.s390x.rpm SHA-256: d66f834d5dd4959d98bfd7779beec89b9d63362ef1c2ab163c0bf2c85d555bbb libreswan-debuginfo-4.9-5.el9_2.5.s390x.rpm SHA-256: ceddaef08872af8dc9db21b3bf12bd1b10650afe48cb8fb971183763b579c11d libreswan-debugsource-4.9-5.el9_2.5.s390x.rpm SHA-256: 7328859ba82989f29e67446a23c8180e503ecbeddf633bc7c52a330e2aef2634 Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.2 SRPM libreswan-4.9-5.el9_2.5.src.rpm SHA-256: 1a81869e3a7210379c07292e149813406c303331e37fb20eb36ce4b0fd907e34 x86_64 libreswan-4.9-5.el9_2.5.x86_64.rpm SHA-256: 9bb70f6883c528222a8d49965fd709c46a60dc5d18387ff725aa8b16f48d46f6 libreswan-debuginfo-4.9-5.el9_2.5.x86_64.rpm SHA-256: 81db9a8d4fbe96afbedf31bce5933ccaaabc7013037b97a23bf04861909e05b8 libreswan-debugsource-4.9-5.el9_2.5.x86_64.rpm SHA-256: 4384188d0ccc497565560a3aff3d4e06e7f1b9d30f7b66cd21735ccfa3e2b403 Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.2 SRPM libreswan-4.9-5.el9_2.5.src.rpm SHA-256: 1a81869e3a7210379c07292e149813406c303331e37fb20eb36ce4b0fd907e34 aarch64 libreswan-4.9-5.el9_2.5.aarch64.rpm SHA-256: 4a039cef627af6fb29f1c8b3f6cf7a2a92e56a838e4e5ada7677dea5c4c8f688 libreswan-debuginfo-4.9-5.el9_2.5.aarch64.rpm SHA-256: 5b8c1960ce1d1f4c1558a8ee35baf8319080d3e935f628b1a859e5867d55a2c7 libreswan-debugsource-4.9-5.el9_2.5.aarch64.rpm SHA-256: 3db2ed8e19b3d28ce0da1ab28a0641f9d9bf3682d1138366e9f07bd9a17c6575 Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.2 SRPM libreswan-4.9-5.el9_2.5.src.rpm SHA-256: 1a81869e3a7210379c07292e149813406c303331e37fb20eb36ce4b0fd907e34 ppc64le libreswan-4.9-5.el9_2.5.ppc64le.rpm SHA-256: c216a37bfb960934ca3265d323e73de9900d13a00a997f70a3924e9dc99486fa libreswan-debuginfo-4.9-5.el9_2.5.ppc64le.rpm SHA-256: e06bb3ad2f92c16eaf4345b037e4b1ca8a8f96a7e2c31e28596ffd38b3f4ee4d libreswan-debugsource-4.9-5.el9_2.5.ppc64le.rpm SHA-256: c2d857f3b6f096dcc2d2eb09d293e4ce71e42efb16844c2c81af09d4f024b10c Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.2 SRPM libreswan-4.9-5.el9_2.5.src.rpm SHA-256: 1a81869e3a7210379c07292e149813406c303331e37fb20eb36ce4b0fd907e34 s390x libreswan-4.9-5.el9_2.5.s390x.rpm SHA-256: d66f834d5dd4959d98bfd7779beec89b9d63362ef1c2ab163c0bf2c85d555bbb libreswan-debuginfo-4.9-5.el9_2.5.s390x.rpm SHA-256: ceddaef08872af8dc9db21b3bf12bd1b10650afe48cb8fb971183763b579c11d libreswan-debugsource-4.9-5.el9_2.5.s390x.rpm SHA-256: 7328859ba82989f29e67446a23c8180e503ecbeddf633bc7c52a330e2aef2634 The Red Hat security contact is secalert@redhat.com . 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