Red Hat Security Advisory: OpenShift Container Platform 4.19.39 bug fix and security update
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 container images for Red Hat OpenShift Container Platform 4.19.39. See the following advisory for the RPM packages for this release: https://access.redhat.com/errata/RHBA-2026:40761 Space precludes documenting all of the container images in this advisory. See the following Release Notes documentation, which will be updated shortly for this release, for details about these changes: https://docs.redhat.com/en/documentation/openshift_container_platform/4.19/html/release_notes/ Security Fix(es): * dnsmasq: NSEC bitmap parsing infinite loop (CVE-2026-4890) * dnsmasq: RRSIG rdlen underflow leading to heap OOB read (CVE-2026-4891) * dnsmasq: DHCPv6 CLID buffer overflow in helper process (CVE-2026-4892) * gnutls: gnutls: Denial of Service via DTLS packet reordering vulnerability (CVE-2026-42009) * gnutls: gnutls: Authentication Bypass via NUL Character in Username (CVE-2026-42010) * dnsmasq: Broken ECS source validation bypass (CVE-2026-4893) * gnutls: gnutls: Information disclosure via heap overread in RSA key exchange (CVE-2026-5260) * glibc: glibc: Heap Buffer Overflow in `scanf` with `%mc` format specifier and large width (CVE-2026-5450) * gnutls: gnutls: Security bypass due to incorrect name constraint handling (CVE-2026-42011) * gnutls: gnutls: Certificate validation bypass due to oversized Subject Alternative Name (CVE-2026-42013) 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. All OpenShift Container Platform 4.19 users are advised to upgrade to these updated packages and images when they are available in the appropriate release channel. 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/4.19/html-single/updating_clusters/index#updating-cluster-cli.
AI Analysis
Technical Summary
This advisory covers Red Hat OpenShift Container Platform 4.19.39, which updates container images and packages to fix several security vulnerabilities. The fixed issues include: dnsmasq NSEC bitmap parsing infinite loop (CVE-2026-4890), RRSIG rdlen underflow causing heap out-of-bounds read (CVE-2026-4891), DHCPv6 CLID buffer overflow (CVE-2026-4892), and ECS source validation bypass (CVE-2026-4893); gnutls denial of service via DTLS packet reordering (CVE-2026-42009), authentication bypass via NUL character in username (CVE-2026-42010), security bypass due to incorrect name constraint handling (CVE-2026-42011), certificate validation bypass due to oversized Subject Alternative Name (CVE-2026-42013), and information disclosure via heap overread in RSA key exchange (CVE-2026-5260); and glibc heap buffer overflow in scanf with %mc format specifier and large width (CVE-2026-5450). The advisory recommends upgrading to 4.19.39 using the OpenShift CLI or web console. Detailed upgrade instructions and image digests are provided by Red Hat.
Potential Impact
The vulnerabilities fixed in this update can lead to denial of service conditions, heap buffer overflows potentially causing crashes or memory corruption, authentication bypasses, information disclosure, and certificate validation bypasses. These issues affect critical components used in OpenShift Container Platform, potentially impacting cluster stability, security, and confidentiality if exploited.
Mitigation Recommendations
Red Hat has released OpenShift Container Platform 4.19.39 containing fixes for these vulnerabilities. All users running versions >=4.19.0 and <4.19.39 are strongly advised to upgrade to 4.19.39 as soon as it is available in their release channel. Upgrades can be performed using the OpenShift CLI (oc) or web console. Detailed upgrade instructions are available at Red Hat's official documentation. No alternative mitigations or workarounds are indicated in the advisory.
Red Hat Security Advisory: OpenShift Container Platform 4.19.39 bug fix and security update
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 container images for Red Hat OpenShift Container Platform 4.19.39. See the following advisory for the RPM packages for this release: https://access.redhat.com/errata/RHBA-2026:40761 Space precludes documenting all of the container images in this advisory. See the following Release Notes documentation, which will be updated shortly for this release, for details about these changes: https://docs.redhat.com/en/documentation/openshift_container_platform/4.19/html/release_notes/ Security Fix(es): * dnsmasq: NSEC bitmap parsing infinite loop (CVE-2026-4890) * dnsmasq: RRSIG rdlen underflow leading to heap OOB read (CVE-2026-4891) * dnsmasq: DHCPv6 CLID buffer overflow in helper process (CVE-2026-4892) * gnutls: gnutls: Denial of Service via DTLS packet reordering vulnerability (CVE-2026-42009) * gnutls: gnutls: Authentication Bypass via NUL Character in Username (CVE-2026-42010) * dnsmasq: Broken ECS source validation bypass (CVE-2026-4893) * gnutls: gnutls: Information disclosure via heap overread in RSA key exchange (CVE-2026-5260) * glibc: glibc: Heap Buffer Overflow in `scanf` with `%mc` format specifier and large width (CVE-2026-5450) * gnutls: gnutls: Security bypass due to incorrect name constraint handling (CVE-2026-42011) * gnutls: gnutls: Certificate validation bypass due to oversized Subject Alternative Name (CVE-2026-42013) 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. All OpenShift Container Platform 4.19 users are advised to upgrade to these updated packages and images when they are available in the appropriate release channel. 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/4.19/html-single/updating_clusters/index#updating-cluster-cli.
Affected software
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This advisory covers Red Hat OpenShift Container Platform 4.19.39, which updates container images and packages to fix several security vulnerabilities. The fixed issues include: dnsmasq NSEC bitmap parsing infinite loop (CVE-2026-4890), RRSIG rdlen underflow causing heap out-of-bounds read (CVE-2026-4891), DHCPv6 CLID buffer overflow (CVE-2026-4892), and ECS source validation bypass (CVE-2026-4893); gnutls denial of service via DTLS packet reordering (CVE-2026-42009), authentication bypass via NUL character in username (CVE-2026-42010), security bypass due to incorrect name constraint handling (CVE-2026-42011), certificate validation bypass due to oversized Subject Alternative Name (CVE-2026-42013), and information disclosure via heap overread in RSA key exchange (CVE-2026-5260); and glibc heap buffer overflow in scanf with %mc format specifier and large width (CVE-2026-5450). The advisory recommends upgrading to 4.19.39 using the OpenShift CLI or web console. Detailed upgrade instructions and image digests are provided by Red Hat.
Potential Impact
The vulnerabilities fixed in this update can lead to denial of service conditions, heap buffer overflows potentially causing crashes or memory corruption, authentication bypasses, information disclosure, and certificate validation bypasses. These issues affect critical components used in OpenShift Container Platform, potentially impacting cluster stability, security, and confidentiality if exploited.
Mitigation Recommendations
Red Hat has released OpenShift Container Platform 4.19.39 containing fixes for these vulnerabilities. All users running versions >=4.19.0 and <4.19.39 are strongly advised to upgrade to 4.19.39 as soon as it is available in their release channel. Upgrades can be performed using the OpenShift CLI (oc) or web console. Detailed upgrade instructions are available at Red Hat's official documentation. No alternative mitigations or workarounds are indicated in the advisory.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_vex
- Csaf Version
- 2.0
- Publisher
- Microsoft Security Response Center
- Advisory Id
- msrc_CVE-2026-4890
- Cve Count
- 1
- Additional Cves
- []
- Cvss Version
- 3.1
Threat ID: 6a175ef1e29bf47b50ede828
Added to database: 05/27/2026, 21:15:29 UTC
Last enriched: 08/16/2026, 16:23:17 UTC
Last updated: 09/05/2026, 22:52:11 UTC
Views: 175
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