Red Hat Security Advisory: OpenShift Container Platform 4.21.26 bug fix and security update
Affects Red HatSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 7.8 High · fixed in Red Hat package updates : patch Red Hat soon.
Data as of 5 Nov 2026, 21:18 UTC
- Patch
- Available – fixed in fe9018d3e94329f1951b00805a8640bc06f56ead, ead66c77303f760f6c30be96e2e20d5a77cef614, 879959a7a2be814dd57568655eafa3d8f4d0309e +4
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 8 May 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 5 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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AI-suggested
Red Hat has released updated container images and RPM packages as part of OpenShift Container Platform 4.21.26 to fix these vulnerabilities. Users should upgrade their OpenShift clusters to version 4.21.26 using the OpenShift CLI (oc) or web console as soon as the updates are available in their release channel. Detailed upgrade instructions are provided in Red Hat's official documentation. No additional mitigations are indicated or required beyond applying the official update.
Description
Red Hat OpenShift Container Platform 4.21.26 includes security updates addressing two kernel vulnerabilities: CVE-2026-43329, which fixes improper checking of the maximum number of actions in netfilter flowtable, and CVE-2026-46323, a use-after-free issue in the Linux kernel's net/gro subsystem due to improper handling of zerocopy skbs. These vulnerabilities have been rated with an Important security impact by Red Hat.
References
- access.redhat.com/errata/RHSA-2026:44262 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2468124 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2479832 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_44262.json (opens in a new tab)