RHSA-2026:56959: Important: osbuild-composer security update

Published Aug 19, 2026
·
Updated

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) 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.

Other sources

Important: osbuild-composer security update

Red Hat

Affected Software

41 affected componentsFixes available
Red Hat Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle
Red Hat Red Hat Enterprise Linux for x86_64 - Extended Life Cycle
Red Hat Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle
Red Hat Red Hat Enterprise Linux for ARM 64 - 4 years of updates
Red Hat Red Hat Enterprise Linux for IBM z Systems - 4 years of updates
Red Hat Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle
Red Hat Red Hat Enterprise Linux Server - AUS
Red Hat Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
Red Hat Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions
redhat/osbuild-composer<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-core<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-core-debuginfo<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-debuginfo<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-debugsource<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-tests-debuginfo<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-worker<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-worker-debuginfo<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-core<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-core-debuginfo<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-debuginfo<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-debugsource<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-tests-debuginfo<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-worker<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-worker-debuginfo<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer<101.3-4.el9_4.4.aa
101.3-4.el9_4.4.aa
redhat/osbuild-composer-core<101.3-4.el9_4.4.aa
101.3-4.el9_4.4.aa
redhat/osbuild-composer-core-debuginfo<101.3-4.el9_4.4.aa
101.3-4.el9_4.4.aa
redhat/osbuild-composer-debuginfo<101.3-4.el9_4.4.aa
101.3-4.el9_4.4.aa
redhat/osbuild-composer-debugsource<101.3-4.el9_4.4.aa
101.3-4.el9_4.4.aa
redhat/osbuild-composer-tests-debuginfo<101.3-4.el9_4.4.aa
101.3-4.el9_4.4.aa
redhat/osbuild-composer-worker<101.3-4.el9_4.4.aa
101.3-4.el9_4.4.aa
redhat/osbuild-composer-worker-debuginfo<101.3-4.el9_4.4.aa
101.3-4.el9_4.4.aa
redhat/osbuild-composer-core<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-core-debuginfo<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-debuginfo<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-debugsource<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-tests-debuginfo<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-worker<101.3-4.el9_4.4
101.3-4.el9_4.4
redhat/osbuild-composer-worker-debuginfo<101.3-4.el9_4.4
101.3-4.el9_4.4

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade redhat/osbuild-composer to a version that resolves this vulnerability.

    Fixed in 101.3-4.el9_4.4
  2. Upgrade

    Upgrade redhat/osbuild-composer-core to a version that resolves this vulnerability.

    Fixed in 101.3-4.el9_4.4
  3. Upgrade

    Upgrade redhat/osbuild-composer-core-debuginfo to a version that resolves this vulnerability.

    Fixed in 101.3-4.el9_4.4
  4. Upgrade

    Upgrade redhat/osbuild-composer-debuginfo to a version that resolves this vulnerability.

    Fixed in 101.3-4.el9_4.4
  5. Upgrade

    Upgrade redhat/osbuild-composer-debugsource to a version that resolves this vulnerability.

    Fixed in 101.3-4.el9_4.4
  6. Upgrade

    Upgrade redhat/osbuild-composer-tests-debuginfo to a version that resolves this vulnerability.

    Fixed in 101.3-4.el9_4.4
  7. Upgrade

    Upgrade redhat/osbuild-composer-worker to a version that resolves this vulnerability.

    Fixed in 101.3-4.el9_4.4
  8. Upgrade

    Upgrade redhat/osbuild-composer-worker-debuginfo to a version that resolves this vulnerability.

    Fixed in 101.3-4.el9_4.4
  9. Upgrade

    Upgrade redhat/osbuild-composer to a version that resolves this vulnerability.

    Fixed in 101.3-4.el9_4.4.aa
  10. Upgrade

    Upgrade redhat/osbuild-composer-core to a version that resolves this vulnerability.

    Fixed in 101.3-4.el9_4.4.aa
  11. Upgrade

    Upgrade redhat/osbuild-composer-core-debuginfo to a version that resolves this vulnerability.

    Fixed in 101.3-4.el9_4.4.aa
  12. Upgrade

    Upgrade redhat/osbuild-composer-debuginfo to a version that resolves this vulnerability.

    Fixed in 101.3-4.el9_4.4.aa
  13. Upgrade

    Upgrade redhat/osbuild-composer-debugsource to a version that resolves this vulnerability.

    Fixed in 101.3-4.el9_4.4.aa
  14. Upgrade

    Upgrade redhat/osbuild-composer-tests-debuginfo to a version that resolves this vulnerability.

    Fixed in 101.3-4.el9_4.4.aa
  15. Upgrade

    Upgrade redhat/osbuild-composer-worker to a version that resolves this vulnerability.

    Fixed in 101.3-4.el9_4.4.aa
  16. Upgrade

    Upgrade redhat/osbuild-composer-worker-debuginfo to a version that resolves this vulnerability.

    Fixed in 101.3-4.el9_4.4.aa
  17. Upgrade

    Upgrade osbuild-composer to a version that resolves this vulnerability.

    Patch CVE-2026-33186

Event History

Aug 19, 2026
Advisory Published
via Red Hat·12:00 AM
Data Sourced
via Red Hat·12:00 AM
RemedyDescriptionAffected Software
Advisory Published
via Red Hat·12:00 PM
Data Sourced
via Red Hat·12:00 PM
Severity

Frequently Asked Questions

1

Which packages are included in this update?

The update covers redhat/osbuild-composer, redhat/osbuild-composer-core, redhat/osbuild-composer-worker, and their listed debuginfo, debugsource, and test-debuginfo packages.

2

Does the advisory provide affected version information or a workaround for systems that cannot be patched immediately?

No affected or fixed version numbers and no temporary mitigation are provided in the supplied advisory data. The referenced CVE page is identified as the source for additional impact and CVSS details.

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