This update addresses CVE-2026-25679 (CVSS 7.5 High), a vulnerability in the Go `net/url` library where incorrect parsing of IPv6 host literals could be exploited. The underlying Go language is affected in versions prior to 1.25.8 and version 1.26.0, requiring an update to Go 1.25.8 or later. The osbuild-composer packages for Red Hat Enterprise Linux 8.6 have been updated to incorporate this fix.
Red Hat Product Errata RHSA-2026:52391 - Security Advisory Issued: 2026-08-10 Updated: 2026-08-10 RHSA-2026:52391 - Security Advisory Overview Updated Packages Synopsis Important: osbuild-composer 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 osbuild-composer is now available for Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On. 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 A service for building customized OS artifacts, such as VM images and OSTree commits, that uses osbuild under the hood. Besides building images for local usage, it can also upload images directly to cloud. It is compatible with composer-cli and cockpit-composer clients. Security Fix(es): net/url: Incorrect parsing of IPv6 host literals in net/url (CVE-2026-25679) 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 - Extended Life Cycle Long Life 8.6 x86_64 Red Hat Enterprise Linux Server - AUS 8.6 x86_64 Fixes BZ - 2445356 - CVE-2026-25679 net/url: Incorrect parsing of IPv6 host literals in net/url CVEs CVE-2026-25679 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 - Extended Life Cycle Long Life 8.6 SRPM osbuild-composer-46.3-7.el8_6.src.rpm SHA-256: 3d555ebf8ee5554551672ef1241c874d6186d2d39e2fc02d80e2cbe4242c5fff x86_64 osbuild-composer-46.3-7.el8_6.x86_64.rpm SHA-256: 95e0ae38ca1211cac6cf8a39dbb8427acaf25aec66b7a8faa09762ae3183c54e osbuild-composer-core-46.3-7.el8_6.x86_64.rpm SHA-256: 04febf86c04eec2676d3ae9a765d5205dd5842e4722523c65970d25e073bf2ae osbuild-composer-core-debuginfo-46.3-7.el8_6.x86_64.rpm SHA-256: bd6a3af228854f5db923b8bfd78f660f491e671051521da8f4c1b3ce6116fae9 osbuild-composer-debuginfo-46.3-7.el8_6.x86_64.rpm SHA-256: 70a257ba5769f9df906b4fc0af4d1b7ae3aef79f6cd855405436e3bae9da6a30 osbuild-composer-debugsource-46.3-7.el8_6.x86_64.rpm SHA-256: 6ac0e97002fee98a473af43782b4d4bdfc4d89863cacc196d4e92bcc385e816d osbuild-composer-dnf-json-46.3-7.el8_6.x86_64.rpm SHA-256: 0358aa886b820f8056c3e6529f2fcc8f9356b45512c37942fe68bf1b515082a4 osbuild-composer-tests-debuginfo-46.3-7.el8_6.x86_64.rpm SHA-256: c2da647ea57f28cdc3f633aec5451d441f8eb9e1f25ac8e2adda870b66a7d983 osbuild-composer-worker-46.3-7.el8_6.x86_64.rpm SHA-256: ecc69bccd465b12d3e4c82ea6bb0b7a317c5d26ef1f944d8edca3214f8f323c1 osbuild-composer-worker-debuginfo-46.3-7.el8_6.x86_64.rpm SHA-256: d01d21088d72b70bb506f40329263cd696558aef12da5addb809981a7d8bc9ca Red Hat Enterprise Linux Server - AUS 8.6 SRPM osbuild-composer-46.3-7.el8_6.src.rpm SHA-256: 3d555ebf8ee5554551672ef1241c874d6186d2d39e2fc02d80e2cbe4242c5fff x86_64 osbuild-composer-46.3-7.el8_6.x86_64.rpm SHA-256: 95e0ae38ca1211cac6cf8a39dbb8427acaf25aec66b7a8faa09762ae3183c54e osbuild-composer-core-46.3-7.el8_6.x86_64.rpm SHA-256: 04febf86c04eec2676d3ae9a765d5205dd5842e4722523c65970d25e073bf2ae osbuild-composer-core-debuginfo-46.3-7.el8_6.x86_64.rpm SHA-256: bd6a3af228854f5db923b8bfd78f660f491e671051521da8f4c1b3ce6116fae9 osbuild-composer-debuginfo-46.3-7.el8_6.x86_64.rpm SHA-256: 70a257ba5769f9df906b4fc0af4d1b7ae3aef79f6cd855405436e3bae9da6a30 osbuild-composer-debugsource-46.3-7.el8_6.x86_64.rpm SHA-256: 6ac0e97002fee98a473af43782b4d4bdfc4d89863cacc196d4e92bcc385e816d osbuild-composer-dnf-json-46.3-7.el8_6.x86_64.rpm SHA-256: 0358aa886b820f8056c3e6529f2fcc8f9356b45512c37942fe68bf1b515082a4 osbuild-composer-tests-debuginfo-46.3-7.el8_6.x86_64.rpm SHA-256: c2da647ea57f28cdc3f633aec5451d441f8eb9e1f25ac8e2adda870b66a7d983 osbuild-composer-worker-46.3-7.el8_6.x86_64.rpm SHA-256: ecc69bccd465b12d3e4c82ea6bb0b7a317c5d26ef1f944d8edca3214f8f323c1 osbuild-composer-worker-debuginfo-46.3-7.el8_6.x86_64.rpm SHA-256: d01d21088d72b70bb506f40329263cd696558aef12da5addb809981a7d8bc9ca The Red Hat security contact is secalert@redhat.com . More contact details at https://access.redhat.com/security/team/contact/ .