Red Hat Security Advisory: OpenShift Container Platform 4.21.40 packages and security update
Affects Red HatSource GCVE Database
Not known to be exploited : upgrade Red Hat x509 to 1.27.3 or 1.26.10 when convenient.
Data as of 29 Oct 2026, 08:25 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 22% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.27.3, 1.26.10
Exploitation evidence
Disclosed: evidence found.
CVE published 21 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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 29 Oct 2026.
What to do
Upgrade crypto/x509 to 1.27.3 or 1.26.10.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Go standard librarycrypto/x509 | Affected
| Fixed in
|
| Go standard librarycrypto/x509 | Affected
| Fixed in
|
Gocrypto/x509pkg:golang/crypto/x509Other threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Red Hat has released updated RPM packages and container images for OpenShift Container Platform 4.21.40 that fix this vulnerability. Upgrades can be performed using the OpenShift CLI (oc) or the web console. Follow the official Red Hat documentation for cluster upgrade procedures to fully apply this security update.
Description
Red Hat OpenShift Container Platform 4.21.40 includes a security update addressing a vulnerability in the golang crypto/x509 package that could allow man-in-the-middle attacks via untrusted intermediate certificates. This update is important for users of OpenShift Container Platform 4.21 and is recommended to be applied through the provided RPM packages and container images. The update mitigates the risk of attackers exploiting certificate validation weaknesses.