RLSA-2026:48790

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):

• google.golang.org/grpc/grpc-go: google.golang.org/grpc/authz: gRPC-Go: Authorization bypass due to improper HTTP/2 path validation (CVE-2026-33186)

• github.com/go-jose/go-jose/v3: github.com/go-jose/go-jose/v4: Go JOSE: Denial of Service via crafted JSON Web Encryption (JWE) object (CVE-2026-34986)

• golang: internal/syscall/unix: Root.Chmod can follow symlinks out of the root (CVE-2026-32282)

• crypto/tls: golang: Go crypto/tls: Denial of Service via multiple TLS 1.3 key update messages (CVE-2026-32283)

• crypto/x509: crypto/tls: golang: Go: Denial of Service vulnerability in certificate chain building (CVE-2026-32280)

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.