Red Hat Product Security released a critical update for the Linux kernel in Red Hat Enterprise Linux 7 Extended Lifecycle Support addressing six vulnerabilities: CVE-2026-23243 (denial of service and memory corruption in RDMA umad), CVE-2026-43037 (clearing skb2->cb[] in ip4ip6_err), CVE-2026-43110 (validation of bsscfg indices in wifi brcmfmac IF events), CVE-2026-43190 (checking remaining length before reading optlen in netfilter xt_tcpmss), CVE-2026-43158 (fixing freemap adjustments when adding xattrs in xfs), and CVE-2026-46243 (rejecting userspace cifs.spnego descriptions in smb client). The advisory includes bug fixes and enhancements and requires a system reboot after applying the update. The advisory references Red Hat's official errata RHSA-2026:27729 and provides links for update instructions.

The vulnerabilities impact the Linux kernel, the core component of the operating system, potentially allowing denial of service, memory corruption, and improper handling of network and filesystem operations. These issues could affect system stability and security, especially in environments using RDMA, IPv6 tunnels, wifi drivers, netfilter, XFS filesystem, and SMB client functionality. The advisory rates the overall impact as critical.

Red Hat has released an official security update for Red Hat Enterprise Linux 7 Extended Lifecycle Support that addresses these vulnerabilities. Users should apply the update as described in the Red Hat advisory RHSA-2026:27729 and reboot their systems to ensure the fixes take effect. No additional mitigation steps are indicated beyond applying the official update and rebooting.