Threats Tagged 'cve-2026-4891'

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.

The dnsmasq packages contain Dnsmasq, a lightweight DNS (Domain Name Server) forwarder and DHCP (Dynamic Host Configuration Protocol) server. Security Fix(es): * dnsmasq: dnsmasq: heap buffer overflow in cache via NAME_ESCAPE expansion (CVE-2026-2291) * 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) * dnsmasq: Broken ECS source validation bypass (CVE-2026-4893) 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.

Multiple security vulnerabilities have been identified in the dnsmasq packages used in Red Hat Enterprise Linux 9. These include heap buffer overflows, infinite loops, out-of-bounds reads, and validation bypasses affecting DNS and DHCP functionality. Red Hat has issued an important security advisory with updates addressing these issues. The vulnerabilities impact various architectures including x86_64, aarch64, s390x, and ppc64le. Users of affected versions are advised to apply the provided updates to mitigate these risks.

The dnsmasq packages contain Dnsmasq, a lightweight DNS (Domain Name Server) forwarder and DHCP (Dynamic Host Configuration Protocol) server. Security Fix(es): * dnsmasq: dnsmasq: heap buffer overflow in cache via NAME_ESCAPE expansion (CVE-2026-2291) * 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) * dnsmasq: Broken ECS source validation bypass (CVE-2026-4893) * dnsmasq: extract_addresses() OOB read via malformed rdlen (CVE-2026-5172) 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.

A heap-based out-of-bounds read vulnerability (CVE-2026-4891) exists in the DNSSEC validation component of dnsmasq, a lightweight DNS forwarder and DHCP server. This vulnerability can be triggered remotely via a crafted DNS packet, potentially causing a denial of service. The issue is part of a set of vulnerabilities addressed in dnsmasq updates. Red Hat has released security advisories and patches for affected versions in Red Hat Enterprise Linux 9 and 10. The vulnerability is rated with medium severity based on CVSS metrics for confidentiality impact but no integrity or availability impact. A fix is available through vendor-provided updates.