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CVE-2026-56862VulnerabilityPublished Updated

Red Hat Security Advisory: OpenShift Container Platform 4.21.34 packages and security update

Affects Red Hat tlsSource GCVE Database

0
Authoritative record:CVE-2026-56862· High 7.5

Not known to be exploited · CVSS 7.5 High : upgrade Red Hat tls to 4.21.34 soon.

Data as of 26 Oct 2026, 12:55 UTC

CVSS 3.1 base score
7.5High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.5% chance of exploitation in 30 days – higher than 46% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 4.21.34
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 13 Aug 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade crypto/tls to 4.21.34.

Affected software

ProductAffectedFixed in
Gocrypto/tlspkg:golang/crypto/tlsOther threatsAffected
  • >=4.21.0 <4.21.34
Fixed in
  • 4.21.34
Ubuntu 14.04 LTSgolang-1.10pkg:deb/ubuntu/golang-1.10?arch=source&distro=trustyOther threatsAffected
  • =1.10.4-2ubuntu1~14.04.1
Fixed in–
Ubuntu 16.04 LTSgolang-1.10pkg:deb/ubuntu/golang-1.10?arch=source&distro=xenialOther threatsAffected
  • =1.10.4-2ubuntu1~16.04.1
  • =1.10.4-2ubuntu1~16.04.2
Fixed in–
Ubuntu 16.04 LTSgolang-1.6pkg:deb/ubuntu/golang-1.6?arch=source&distro=xenialOther threatsAffected
  • 1.6-0ubuntu1 – 1.6.2-0ubuntu5~16.04.4
10 affected builds
Fixed in–
Ubuntu Pro 16.04 LTSgolang-1.13pkg:deb/ubuntu/golang-1.13?arch=source&distro=esm-apps/xenialOther threatsAffected
  • 1.13.8-1ubuntu1~16.04.2 – 1.13.8-1ubuntu1~16.04.3+esm3
4 affected builds
Fixed in–
Ubuntu Pro 16.04 LTSgolang-1.18pkg:deb/ubuntu/golang-1.18?arch=source&distro=esm-apps/xenialOther threatsAffected
  • =1.18.1-1ubuntu1~16.04.6
  • =1.18.1-1ubuntu1~16.04.6+esm1
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

Red Hat OpenShift Container Platform is Red Hat's cloud computing Kubernetes application platform solution designed for on-premise or private cloud deployments. This advisory contains the RPM packages for Red Hat OpenShift Container Platform 4.21.34. See the following advisory for the container images for this release: https://access.redhat.com/errata/RHSA-2026:68546 Security Fix(es): * crypto/tls: golang: Golang crypto/tls: Denial of Service via indefinite KeyUpdate messages (CVE-2026-56862) 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. To check for available updates, use the OpenShift CLI (oc) or web console. Instructions for upgrading a cluster are available at https://docs.redhat.com/en/documentation/openshift_container_platform/4.21/html-single/updating_clusters/index#updating-cluster-cli.

References

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