RHSA-2026:1381 — Security Advisory

An update for osbuild-composer is now available for Red Hat Enterprise Linux 9.

Red Hat Product Security has rated this update as having a security impact of Moderate. 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.

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):

• golang: archive/tar: Unbounded allocation when parsing GNU sparse map (CVE-2025-58183)

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.