RHSA-2026:57482HighCVSS 7.5

Red Hat Security Advisory: OpenShift Container Platform 4.18.54 packages and security update

Published
August 26, 2026
Last Modified
September 19, 2026

🔗 CVE IDs covered (7)

CVE-2026-25679 →CVE-2026-27145 →CVE-2026-32280 →CVE-2026-33811 →CVE-2026-39820 →CVE-2026-42499 →CVE-2026-42504 →

📋 Description

CVE-2026-25679 — net/url: Incorrect parsing of IPv6 host literals in net/url CVE-2026-27145 — crypto/x509: golang: golang crypto/x509: Denial of Service via excessive processing of DNS SAN entries CVE-2026-32280 — crypto/x509: crypto/tls: golang: Go: Denial of Service vulnerability in certificate chain building CVE-2026-33811 — net: golang: Go net package: Denial of Service via long CNAME response in LookupCNAME CVE-2026-39820 — net/mail: golang: Go net/mail: Denial of Service via crafted email inputs CVE-2026-42499 — net/mail: golang: net/mail: Denial of Service via pathological email address parsing CVE-2026-42504 — mime: golang: Golang MIME: Denial of Service via maliciously-crafted MIME header

🎯 Affected products200

  • Red Hat OpenShift Container Platform 4.18
  • butane-0:0.23.0-5.rhaos4.18.el8.aarch64 as a component of Red Hat OpenShift Container Platform 4.18
  • butane-0:0.23.0-5.rhaos4.18.el8.ppc64le as a component of Red Hat OpenShift Container Platform 4.18
  • butane-0:0.23.0-5.rhaos4.18.el8.s390x as a component of Red Hat OpenShift Container Platform 4.18
  • butane-0:0.23.0-5.rhaos4.18.el8.src as a component of Red Hat OpenShift Container Platform 4.18
  • butane-0:0.23.0-5.rhaos4.18.el8.x86_64 as a component of Red Hat OpenShift Container Platform 4.18
  • butane-debuginfo-0:0.23.0-5.rhaos4.18.el8.aarch64 as a component of Red Hat OpenShift Container Platform 4.18
  • butane-debuginfo-0:0.23.0-5.rhaos4.18.el8.ppc64le as a component of Red Hat OpenShift Container Platform 4.18
  • butane-debuginfo-0:0.23.0-5.rhaos4.18.el8.s390x as a component of Red Hat OpenShift Container Platform 4.18
  • butane-debuginfo-0:0.23.0-5.rhaos4.18.el8.x86_64 as a component of Red Hat OpenShift Container Platform 4.18
  • butane-debugsource-0:0.23.0-5.rhaos4.18.el8.aarch64 as a component of Red Hat OpenShift Container Platform 4.18
  • butane-debugsource-0:0.23.0-5.rhaos4.18.el8.ppc64le as a component of Red Hat OpenShift Container Platform 4.18
  • butane-debugsource-0:0.23.0-5.rhaos4.18.el8.s390x as a component of Red Hat OpenShift Container Platform 4.18
  • butane-debugsource-0:0.23.0-5.rhaos4.18.el8.x86_64 as a component of Red Hat OpenShift Container Platform 4.18
  • butane-redistributable-0:0.23.0-5.rhaos4.18.el8.noarch as a component of Red Hat OpenShift Container Platform 4.18
  • containernetworking-plugins-1:1.4.0-10.rhaos4.18.el8.aarch64 as a component of Red Hat OpenShift Container Platform 4.18
  • containernetworking-plugins-1:1.4.0-10.rhaos4.18.el8.ppc64le as a component of Red Hat OpenShift Container Platform 4.18
  • containernetworking-plugins-1:1.4.0-10.rhaos4.18.el8.s390x as a component of Red Hat OpenShift Container Platform 4.18
  • containernetworking-plugins-1:1.4.0-10.rhaos4.18.el8.src as a component of Red Hat OpenShift Container Platform 4.18
  • containernetworking-plugins-1:1.4.0-10.rhaos4.18.el8.x86_64 as a component of Red Hat OpenShift Container Platform 4.18
  • containernetworking-plugins-debuginfo-1:1.4.0-10.rhaos4.18.el8.aarch64 as a component of Red Hat OpenShift Container Platform 4.18
  • containernetworking-plugins-debuginfo-1:1.4.0-10.rhaos4.18.el8.ppc64le as a component of Red Hat OpenShift Container Platform 4.18
  • containernetworking-plugins-debuginfo-1:1.4.0-10.rhaos4.18.el8.s390x as a component of Red Hat OpenShift Container Platform 4.18
  • containernetworking-plugins-debuginfo-1:1.4.0-10.rhaos4.18.el8.x86_64 as a component of Red Hat OpenShift Container Platform 4.18
  • containernetworking-plugins-debugsource-1:1.4.0-10.rhaos4.18.el8.aarch64 as a component of Red Hat OpenShift Container Platform 4.18
  • containernetworking-plugins-debugsource-1:1.4.0-10.rhaos4.18.el8.ppc64le as a component of Red Hat OpenShift Container Platform 4.18
  • containernetworking-plugins-debugsource-1:1.4.0-10.rhaos4.18.el8.s390x as a component of Red Hat OpenShift Container Platform 4.18
  • containernetworking-plugins-debugsource-1:1.4.0-10.rhaos4.18.el8.x86_64 as a component of Red Hat OpenShift Container Platform 4.18
  • cri-o-0:1.31.13-11.rhaos4.18.git817a650.el9.aarch64 as a component of Red Hat OpenShift Container Platform 4.18
  • cri-o-0:1.31.13-11.rhaos4.18.git817a650.el9.ppc64le as a component of Red Hat OpenShift Container Platform 4.18
  • +170 more not shown

✅ Remediation

For OpenShift Container Platform 4.18 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this asynchronous errata update: https://docs.redhat.com/en/documentation/openshift_container_platform/4.18/html/release_notes/ Workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability. 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: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. 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 (10)