Red Hat has issued an Important security update for libreswan addressing four denial-of-service vulnerabilities (CVE-2026-50721, CVE-2026-50722, CVE-2026-12413, CVE-2026-14957) with CVSS scores up to 8.1 (High), which can be triggered via malformed RSA-SHA1 authentication payloads, IKEv2 fragmentation, or badly formatted X.509 certificates. Affected versions are libreswan prior to version 5.3.1, with CVE-2026-12413 specifically affecting versions 4.6 through 5.3. The fix requires upgrading libreswan to version 5.3.1.
Red Hat Product Errata RHSA-2026:46396 - Security Advisory Issued: 2026-07-27 Updated: 2026-07-27 RHSA-2026:46396 - 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 8. 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 8 x86_64 Red Hat Enterprise Linux for IBM z Systems 8 s390x Red Hat Enterprise Linux for Power, little endian 8 ppc64le Red Hat Enterprise Linux for ARM 64 8 aarch64 Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 8.10 x86_64 Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 8.10 aarch64 Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 8.10 ppc64le Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 8.10 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 8 SRPM libreswan-4.12-2.el8_10.6.src.rpm SHA-256: a96777577e2db05c8265ba57f2567f2d3d0f690b640ed7b532988aead7849d2f x86_64 libreswan-4.12-2.el8_10.6.x86_64.rpm SHA-256: 369c16d45af2a4bb1744245a66d2eeee24a821b004b4a5614c252a49c36ded6e libreswan-debuginfo-4.12-2.el8_10.6.x86_64.rpm SHA-256: c44d8d06fa1003b8f39a7b9dc34b721db0f7e209df2318d4534aa66492147ad9 libreswan-debugsource-4.12-2.el8_10.6.x86_64.rpm SHA-256: bfb1c7b61427afae80e808184dd7a72b800c01c46ebc741723f5e8c7ccd49bf5 Red Hat Enterprise Linux for IBM z Systems 8 SRPM libreswan-4.12-2.el8_10.6.src.rpm SHA-256: a96777577e2db05c8265ba57f2567f2d3d0f690b640ed7b532988aead7849d2f s390x libreswan-4.12-2.el8_10.6.s390x.rpm SHA-256: e406b9b524f460b1b0eee4f4f7dc67da4aebae3f83dcf8b9d95f23313da2d33e libreswan-debuginfo-4.12-2.el8_10.6.s390x.rpm SHA-256: b95dbd347de80ab2ed88e2345097b7fc64b6abcadda607d2eb185362de80b144 libreswan-debugsource-4.12-2.el8_10.6.s390x.rpm SHA-256: e80d4413af670dc467628b80063ac57094f4b09a2efed17af51e2a4ea428d461 Red Hat Enterprise Linux for Power, little endian 8 SRPM libreswan-4.12-2.el8_10.6.src.rpm SHA-256: a96777577e2db05c8265ba57f2567f2d3d0f690b640ed7b532988aead7849d2f ppc64le libreswan-4.12-2.el8_10.6.ppc64le.rpm SHA-256: 9886f0786aab850cf9277a3114b06ecb24abff70134c8cb8b22aa5f0d2b5b2c7 libreswan-debuginfo-4.12-2.el8_10.6.ppc64le.rpm SHA-256: 4560d5f603b136bff2948046b38db8d51fbcb10db45c6b511aa6b7b8e751f56f libreswan-debugsource-4.12-2.el8_10.6.ppc64le.rpm SHA-256: 611994de53e27127545a4b3dc949e280a3fe2e7de98f083dac7e59b16ccc8c3f Red Hat Enterprise Linux for ARM 64 8 SRPM libreswan-4.12-2.el8_10.6.src.rpm SHA-256: a96777577e2db05c8265ba57f2567f2d3d0f690b640ed7b532988aead7849d2f aarch64 libreswan-4.12-2.el8_10.6.aarch64.rpm SHA-256: 7aa54f542e6e98a8e90261ea61c1e18dd65fdeaaf4ae13fc9006681240f5ec39 libreswan-debuginfo-4.12-2.el8_10.6.aarch64.rpm SHA-256: 8f599c571273d511c6807be4f8603a6f5990925a67a6eba7789e0ecc33103980 libreswan-debugsource-4.12-2.el8_10.6.aarch64.rpm SHA-256: 9532c696375fbea3429a1ac3609952a58670028c56d3c94bce12f68a9ee8df02 Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 8.10 SRPM libreswan-4.12-2.el8_10.6.src.rpm SHA-256: a96777577e2db05c8265ba57f2567f2d3d0f690b640ed7b532988aead7849d2f x86_64 libreswan-4.12-2.el8_10.6.x86_64.rpm SHA-256: 369c16d45af2a4bb1744245a66d2eeee24a821b004b4a5614c252a49c36ded6e libreswan-debuginfo-4.12-2.el8_10.6.x86_64.rpm SHA-256: c44d8d06fa1003b8f39a7b9dc34b721db0f7e209df2318d4534aa66492147ad9 libreswan-debugsource-4.12-2.el8_10.6.x86_64.rpm SHA-256: bfb1c7b61427afae80e808184dd7a72b800c01c46ebc741723f5e8c7ccd49bf5 Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 8.10 SRPM libreswan-4.12-2.el8_10.6.src.rpm SHA-256: a96777577e2db05c8265ba57f2567f2d3d0f690b640ed7b532988aead7849d2f aarch64 libreswan-4.12-2.el8_10.6.aarch64.rpm SHA-256: 7aa54f542e6e98a8e90261ea61c1e18dd65fdeaaf4ae13fc9006681240f5ec39 libreswan-debuginfo-4.12-2.el8_10.6.aarch64.rpm SHA-256: 8f599c571273d511c6807be4f8603a6f5990925a67a6eba7789e0ecc33103980 libreswan-debugsource-4.12-2.el8_10.6.aarch64.rpm SHA-256: 9532c696375fbea3429a1ac3609952a58670028c56d3c94bce12f68a9ee8df02 Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 8.10 SRPM libreswan-4.12-2.el8_10.6.src.rpm SHA-256: a96777577e2db05c8265ba57f2567f2d3d0f690b640ed7b532988aead7849d2f ppc64le libreswan-4.12-2.el8_10.6.ppc64le.rpm SHA-256: 9886f0786aab850cf9277a3114b06ecb24abff70134c8cb8b22aa5f0d2b5b2c7 libreswan-debuginfo-4.12-2.el8_10.6.ppc64le.rpm SHA-256: 4560d5f603b136bff2948046b38db8d51fbcb10db45c6b511aa6b7b8e751f56f libreswan-debugsource-4.12-2.el8_10.6.ppc64le.rpm SHA-256: 611994de53e27127545a4b3dc949e280a3fe2e7de98f083dac7e59b16ccc8c3f Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 8.10 SRPM libreswan-4.12-2.el8_10.6.src.rpm SHA-256: a96777577e2db05c8265ba57f2567f2d3d0f690b640ed7b532988aead7849d2f s390x libreswan-4.12-2.el8_10.6.s390x.rpm SHA-256: e406b9b524f460b1b0eee4f4f7dc67da4aebae3f83dcf8b9d95f23313da2d33e libreswan-debuginfo-4.12-2.el8_10.6.s390x.rpm SHA-256: b95dbd347de80ab2ed88e2345097b7fc64b6abcadda607d2eb185362de80b144 libreswan-debugsource-4.12-2.el8_10.6.s390x.rpm SHA-256: e80d4413af670dc467628b80063ac57094f4b09a2efed17af51e2a4ea428d461 The Red Hat security contact is secalert@redhat.com . More contact details at https://access.redhat.com/security/team/contact/ .