{ "document": { "aggregate_severity": { "text": "Important" }, "category": "csaf_security_advisory", "csaf_version": "2.0", "distribution": { "text": "TuxCare License Agreement", "tlp": { "label": "WHITE", "url": "https://www.first.org/tlp/" } }, "lang": "en", "notes": [ { "category": "legal_disclaimer", "text": "This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Cloud Linux Inc. and provide a link to the original.", "title": "Terms of Use" }, { "category": "details", "text": "CVE-2026-72693: fix openvt -u process ownership validation", "title": "Details" } ], "publisher": { "category": "vendor", "contact_details": "https://tuxcare.com/contact/", "name": "TuxCare", "namespace": "https://tuxcare.com/" }, "references": [ { "category": "self", "summary": "https://cve.tuxcare.com/els/releases/CLSA-2026:1788600455", "url": "https://cve.tuxcare.com/els/releases/CLSA-2026:1788600455" }, { "category": "self", "summary": "Canonical URL", "url": "https://security.tuxcare.com/csaf/v2/els_os/almalinux9.2esu/advisories/2026/clsa-2026_1788600455.json" } ], "tracking": { "current_release_date": "2026-09-05T09:28:20Z", "generator": { "date": "2026-09-05T09:28:20Z", "engine": { "name": "pyCSAF" } }, "id": "CLSA-2026:1788600455", "initial_release_date": "2026-09-05T09:28:20Z", "revision_history": [ { "date": "2026-09-05T09:28:20Z", "number": "1", "summary": "Initial version" } ], "status": "final", "version": "1" }, "title": "kbd: Fix of CVE-2026-72693" }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_name", "name": "AlmaLinux 9.2", "product": { "name": "AlmaLinux 9.2", "product_id": "AlmaLinux-9.2", "product_identification_helper": { "cpe": "cpe:2.3:o:almalinux:almalinux:9.2:*:*:*:*:*:*:*" } } } ], "category": "product_family", "name": "AlmaLinux" } ], "category": "vendor", "name": "AlmaLinux OS Foundation" }, { "branches": [ { "branches": [ { "category": "product_version", "name": "kbd-0:2.4.0-8.el9.tuxcare.els1.x86_64", "product": { "name": "kbd-0:2.4.0-8.el9.tuxcare.els1.x86_64", "product_id": "kbd-0:2.4.0-8.el9.tuxcare.els1.x86_64", "product_identification_helper": { "purl": "pkg:rpm/tuxcare/kbd@2.4.0-8.el9.tuxcare.els1?arch=x86_64" } } } ], "category": "architecture", "name": "x86_64" }, { "branches": [ { "category": "product_version", "name": "kbd-legacy-0:2.4.0-8.el9.tuxcare.els1.noarch", "product": { "name": "kbd-legacy-0:2.4.0-8.el9.tuxcare.els1.noarch", "product_id": "kbd-legacy-0:2.4.0-8.el9.tuxcare.els1.noarch", "product_identification_helper": { "purl": "pkg:rpm/tuxcare/kbd-legacy@2.4.0-8.el9.tuxcare.els1?arch=noarch" } } }, { "category": "product_version", "name": "kbd-misc-0:2.4.0-8.el9.tuxcare.els1.noarch", "product": { "name": "kbd-misc-0:2.4.0-8.el9.tuxcare.els1.noarch", "product_id": "kbd-misc-0:2.4.0-8.el9.tuxcare.els1.noarch", "product_identification_helper": { "purl": "pkg:rpm/tuxcare/kbd-misc@2.4.0-8.el9.tuxcare.els1?arch=noarch" } } } ], "category": "architecture", "name": "noarch" } ], "category": "vendor", "name": "TuxCare" } ], "relationships": [ { "category": "default_component_of", "full_product_name": { "name": "kbd-0:2.4.0-8.el9.tuxcare.els1.x86_64 as a component of AlmaLinux 9.2", "product_id": "AlmaLinux-9.2:kbd-0:2.4.0-8.el9.tuxcare.els1.x86_64" }, "product_reference": "kbd-0:2.4.0-8.el9.tuxcare.els1.x86_64", "relates_to_product_reference": "AlmaLinux-9.2" }, { "category": "default_component_of", "full_product_name": { "name": "kbd-legacy-0:2.4.0-8.el9.tuxcare.els1.noarch as a component of AlmaLinux 9.2", "product_id": "AlmaLinux-9.2:kbd-legacy-0:2.4.0-8.el9.tuxcare.els1.noarch" }, "product_reference": "kbd-legacy-0:2.4.0-8.el9.tuxcare.els1.noarch", "relates_to_product_reference": "AlmaLinux-9.2" }, { "category": "default_component_of", "full_product_name": { "name": "kbd-misc-0:2.4.0-8.el9.tuxcare.els1.noarch as a component of AlmaLinux 9.2", "product_id": "AlmaLinux-9.2:kbd-misc-0:2.4.0-8.el9.tuxcare.els1.noarch" }, "product_reference": "kbd-misc-0:2.4.0-8.el9.tuxcare.els1.noarch", "relates_to_product_reference": "AlmaLinux-9.2" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-72693", "cwe": { "id": "CWE-284", "name": "Improper Access Control" }, "notes": [ { "category": "description", "text": "`openvt -u` is intended to identify the owner of the current VT and then execute `login` as that user from a privileged context. In the documented `kbrequest`/init usage, the ownership test in `authenticate_user()` relies on `stat(\"/proc//fd/0\")`. `stat()` on `/proc//fd/0` follows the symlink to the underlying TTY device node. As a result, `buf.st_uid` reflects the owner of the TTY node rather than the owner of the process holding the file descriptor. If the TTY owner returns to `root` or the getty owner after logout while an unprivileged process still has `fd 0` attached to that TTY, the check can incorrectly treat that process as belonging to the privileged console owner. Once that check succeeds, the `-u` path executes a passwordless login as the selected user. In the documented `kbrequest`/init deployment using `openvt -us`, this can result in passwordless `login -f root` on the spawned VT. This report establishes that privilege escalation path for that documented deployment; it does not claim equivalent reachability for deployments that do not use `openvt -u` from a privileged `kbrequest`/init path.", "title": "Vulnerability description" } ], "product_status": { "fixed": [ "AlmaLinux-9.2:kbd-0:2.4.0-8.el9.tuxcare.els1.x86_64", "AlmaLinux-9.2:kbd-legacy-0:2.4.0-8.el9.tuxcare.els1.noarch", "AlmaLinux-9.2:kbd-misc-0:2.4.0-8.el9.tuxcare.els1.noarch" ] }, "references": [ { "category": "self", "summary": "Canonical URL", "url": "https://cve.tuxcare.com/els/cve/CVE-2026-72693" }, { "category": "external", "summary": "https://access.redhat.com/errata/RHSA-2026:41136", "url": "https://access.redhat.com/errata/RHSA-2026:41136" }, { "category": "external", "summary": "https://access.redhat.com/errata/RHSA-2026:57597", "url": "https://access.redhat.com/errata/RHSA-2026:57597" }, { "category": "external", "summary": "https://access.redhat.com/errata/RHSA-2026:57610", "url": "https://access.redhat.com/errata/RHSA-2026:57610" }, { "category": "external", "summary": "https://access.redhat.com/errata/RHSA-2026:60440", "url": "https://access.redhat.com/errata/RHSA-2026:60440" }, { "category": "external", "summary": "https://access.redhat.com/security/cve/CVE-2026-72693", "url": "https://access.redhat.com/security/cve/CVE-2026-72693" }, { "category": "external", "summary": "https://bugzilla.redhat.com/show_bug.cgi?id=2462115", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2462115" } ], "release_date": "2026-08-11T09:17:00Z", "remediations": [ { "category": "vendor_fix", "date": "2026-09-05T09:27:37.962435Z", "details": "Details on how to apply the fix are available at: https://cve.tuxcare.com/els/releases/CLSA-2026:1788600455", "product_ids": [ "AlmaLinux-9.2:kbd-0:2.4.0-8.el9.tuxcare.els1.x86_64", "AlmaLinux-9.2:kbd-legacy-0:2.4.0-8.el9.tuxcare.els1.noarch", "AlmaLinux-9.2:kbd-misc-0:2.4.0-8.el9.tuxcare.els1.noarch" ], "url": "https://cve.tuxcare.com/els/releases/CLSA-2026:1788600455" } ], "threats": [ { "category": "impact", "details": "Important" } ] } ] }