This Red Hat security update addresses two high-severity vulnerabilities in the `pcs` cluster configuration tool: a Denial of Service (DoS) in Tornado (CVE-2026-31958, CVSS 7.5) via large multipart bodies and arbitrary code execution in lodash (CVE-2026-4800, CVSS 8.1) via untrusted input in template imports. The affected Tornado versions are below 6.5.5, and affected lodash/lodash-es/lodash-rails versions are below 4.17.21. The fix is included in the updated `pcs` packages for Red Hat Enterprise Linux 8.4 support channels.
Red Hat Product Errata RHSA-2026:11493 - Security Advisory Issued: 2026-04-29 Updated: 2026-04-29 RHSA-2026:11493 - Security Advisory Overview Updated Packages Synopsis Important: pcs security update Type/Severity Security Advisory: Important Red Hat Lightspeed patch analysis Identify and remediate systems affected by this advisory. View affected systems Topic An update for pcs is now available for Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section. Description The pcs packages provide a command-line configuration system for the Pacemaker and Corosync utilities. Security Fix(es): tornado-python: Tornado: Denial of Service via large multipart bodies (CVE-2026-31958) lodash: lodash: Arbitrary code execution via untrusted input in template imports (CVE-2026-4800) 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. Solution For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Affected Products Red Hat Enterprise Linux High Availability for x86_64 - Advanced Update Support 8.4 x86_64 Red Hat Enterprise Linux High Availability for x86_64 - Extended Update Support Extension 8.4 x86_64 Fixes BZ - 2446765 - CVE-2026-31958 tornado-python: Tornado: Denial of Service via large multipart bodies BZ - 2453496 - CVE-2026-4800 lodash: lodash: Arbitrary code execution via untrusted input in template imports CVEs CVE-2026-4800 CVE-2026-31958 References https://access.redhat.com/security/updates/classification/#important Note: More recent versions of these packages may be available. Click a package name for more details. Red Hat Enterprise Linux High Availability for x86_64 - Advanced Update Support 8.4 SRPM pcs-0.10.8-1.el8_4.11.src.rpm SHA-256: c02b7b78337c5be8f3601af23abadb49726c7906d9752deff27397a1607e99f6 x86_64 pcs-0.10.8-1.el8_4.11.x86_64.rpm SHA-256: d114e1698be2670f28d17c38482c5c5e0d202e5560b2e1c6ce125e8197f14966 pcs-snmp-0.10.8-1.el8_4.11.x86_64.rpm SHA-256: 54ad07bc88e3013efacfb4e96698a627d900da72a3f81b857e092805e3a77a2c Red Hat Enterprise Linux High Availability for x86_64 - Extended Update Support Extension 8.4 SRPM pcs-0.10.8-1.el8_4.11.src.rpm SHA-256: c02b7b78337c5be8f3601af23abadb49726c7906d9752deff27397a1607e99f6 x86_64 pcs-0.10.8-1.el8_4.11.x86_64.rpm SHA-256: d114e1698be2670f28d17c38482c5c5e0d202e5560b2e1c6ce125e8197f14966 pcs-snmp-0.10.8-1.el8_4.11.x86_64.rpm SHA-256: 54ad07bc88e3013efacfb4e96698a627d900da72a3f81b857e092805e3a77a2c The Red Hat security contact is secalert@redhat.com . More contact details at https://access.redhat.com/security/team/contact/ .