RHSA-2026:42946HighCVSS 7.5

Red Hat Security Advisory: rhc-worker-playbook security, bug fix, and enhancement update

Published
July 21, 2026
Last Modified
October 31, 2026

🔗 CVE IDs covered (4)

CVE-2026-27145 →CVE-2026-33811 →CVE-2026-42504 →CVE-2026-11837 →

📋 Description

CVE-2026-11837 — ansible-collection-ansible-posix: ansible.posix authorized_key: local privilege escalation via symlink-following chown CVE-2026-27145 — crypto/x509: golang: golang crypto/x509: Denial of Service via excessive processing of DNS SAN entries CVE-2026-33811 — net: golang: Go net package: Denial of Service via long CNAME response in LookupCNAME CVE-2026-42504 — mime: golang: Golang MIME: Denial of Service via maliciously-crafted MIME header

🎯 Affected products14

  • Red Hat Enterprise Linux AppStream (v. 10)
  • rhc-worker-playbook-0:0.2.10-1.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • rhc-worker-playbook-0:0.2.10-1.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • rhc-worker-playbook-0:0.2.10-1.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • rhc-worker-playbook-0:0.2.10-1.el10_2.src as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • rhc-worker-playbook-0:0.2.10-1.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • rhc-worker-playbook-debuginfo-0:0.2.10-1.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • rhc-worker-playbook-debuginfo-0:0.2.10-1.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • rhc-worker-playbook-debuginfo-0:0.2.10-1.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • rhc-worker-playbook-debuginfo-0:0.2.10-1.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • rhc-worker-playbook-debugsource-0:0.2.10-1.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • rhc-worker-playbook-debugsource-0:0.2.10-1.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • rhc-worker-playbook-debugsource-0:0.2.10-1.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • rhc-worker-playbook-debugsource-0:0.2.10-1.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Workaround: The following practices would help for avoiding exposure and mitigate this flaw: 1) Do not run the ansible.posix authorized_key module with elevated privileges against untrusted user accounts. 2) Validate that target user home directories do not contain unexpected symbolic links before running playbooks. Workaround: A flaw was found in the Go standard library crypto/x509 package. When verifying a TLS certificate hostname, VerifyHostname processed each DNS Subject Alternative Name (SAN) entry in a loop and repeatedly split the candidate hostname on "." characters. For certificates with a very large DNS SAN list, CPU use could grow quadratically with the number of SAN entries and hostname labels. Because hostname verification runs before the certificate chain is built, this overhead can occur even when the certificate is not trusted. Red Hat rates this issue as Important. It affects Red Hat products that include the Go standard library crypto/x509 code from an affected Go toolchain version (before Go 1.25.11, or from Go 1.26.0 through Go 1.26.3). Applications and container images built with a fixed Go release (1.25.11 or later, or 1.26.4 or later) are not affected. Community distributions such as Fedora are also affected. Upstream fix: Go 1.25.11 and Go 1.26.4 (GO-2026-5037). Workaround: To mitigate this issue, applications can be configured to use the pure Go DNS resolver instead of the `cgo` DNS resolver. This can be achieved by setting the `GODEBUG` environment variable to `netdns=go`. For example, to run a Go application with this mitigation: `GODEBUG=netdns=go /path/to/your/go/application`. This change may require restarting affected applications or services to take effect. Users should verify that this change does not negatively impact DNS resolution for their specific application environment. Workaround: To mitigate this issue, restrict network access to services that process MIME headers from untrusted sources. Implement input validation and sanitization for all incoming data, especially MIME headers, to prevent maliciously crafted content from being processed by applications utilizing the vulnerable Golang MIME package.

🔗 References (6)