Red Hat Security Advisory: OpenShift Container Platform 4.21.30 packages and security update

Fixed packages 14

Vulnerabilities 1

• High 7.5
  CVE-2026-42504

  Quadratic complexity in WordDecoder.DecodeHeader in mime

  Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU.

  Go standard library mime golang go Debian Ubuntu Azure Linux Alpine Wolfi Go
  Jun 2, 2026

References

• article
  https://access.redhat.com/security/updates/classification/#important
• report
  https://bugzilla.redhat.com/show_bug.cgi?id=2484204
• advisory
  https://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_57456.json
• report
  https://access.redhat.com/security/cve/CVE-2026-42504
• advisory
  https://www.cve.org/CVERecord?id=CVE-2026-42504
• advisory
  https://nvd.nist.gov/vuln/detail/CVE-2026-42504
• article
  https://go.dev/cl/774481
• article
  https://go.dev/issue/79217
• article
  https://groups.google.com/g/golang-announce/c/tKs3rmcBcKw
• advisory
  https://pkg.go.dev/vuln/GO-2026-5038