# CVE-2026-72693: Kbd: local privilege escalation in openvt via incorrect process owner verification allowing passwordless root login > Local attackers can gain root privileges via passwordless login if openvt -u is used in kbrequest/init due to incorrect process owner verification. - **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 11 Aug 2026 - **Updated:** 9 Oct 2026 - **Also known as:** ALSA-2026:57597, ALSA-2026:57610, ALSA-2026:78951, AZL-95928, CLSA-2026-1788265535, CLSA-2026-1788600455, DEBIAN-CVE-2026-72693, GHSA-6766-cx7r-c5q6, MGASA-2026-0444, OESA-2026-3505, RHSA-2026:41136, RHSA-2026:57597, RHSA-2026:57610, RHSA-2026:78951, RLSA-2026:57597, RLSA-2026:57610, RLSA-2026:78951, ROOT-OS-DEBIAN-12-CVE-2026-72693, SUSE-SU-2026:23742-1, SUSE-SU-2026:23844-1, SUSE-SU-2026:23893-1, SUSE-SU-2026:23911-1, SUSE-SU-2026:4207-1, SUSE-SU-2026:4211-1, UBUNTU-CVE-2026-72693, openSUSE-SU-2026:21939-1 ## What is CVE-2026-72693? CVE-2026-72693 is a high-severity vulnerability in Red Hat Enterprise Linux 10, published on 11 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description `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. Weakness: CWE-284 (Improper Access Control) ## Which versions are affected by CVE-2026-72693? | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `kbd` | AlmaLinux:10 | All versions | 2.6.4-8.el10_2 | | `kbd-legacy` | AlmaLinux:10 | All versions | 2.6.4-8.el10_2 | | `kbd-misc` | AlmaLinux:10 | All versions | 2.6.4-8.el10_2 | | `kbd` | AlmaLinux:8 | All versions | 2.0.4-11.el8_10.1 | | `kbd-legacy` | AlmaLinux:8 | All versions | 2.0.4-11.el8_10.1 | | `kbd-misc` | AlmaLinux:8 | All versions | 2.0.4-11.el8_10.1 | | `kbd` | AlmaLinux:9 | All versions | 2.4.0-12.el9_8 | | `kbd-legacy` | AlmaLinux:9 | All versions | 2.4.0-12.el9_8 | | `kbd-misc` | AlmaLinux:9 | All versions | 2.4.0-12.el9_8 | | `kbd` | Red Hat:enterprise_linux:10.2 | All versions | 0:2.6.4-8.el10_2 | | `kbd-debuginfo` | Red Hat:enterprise_linux:10.2 | All versions | 0:2.6.4-8.el10_2 | | `kbd-debugsource` | Red Hat:enterprise_linux:10.2 | All versions | 0:2.6.4-8.el10_2 | | `kbd-legacy` | Red Hat:enterprise_linux:10.2 | All versions | 0:2.6.4-8.el10_2 | | `kbd-misc` | Red Hat:enterprise_linux:10.2 | All versions | 0:2.6.4-8.el10_2 | | `kbd` | Red Hat:enterprise_linux:8::baseos | All versions | 0:2.0.4-11.el8_10.1 | | `kbd-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:2.0.4-11.el8_10.1 | | `kbd-debugsource` | Red Hat:enterprise_linux:8::baseos | All versions | 0:2.0.4-11.el8_10.1 | | `kbd-legacy` | Red Hat:enterprise_linux:8::baseos | All versions | 0:2.0.4-11.el8_10.1 | | `kbd-misc` | Red Hat:enterprise_linux:8::baseos | All versions | 0:2.0.4-11.el8_10.1 | | `kbd` | Red Hat:enterprise_linux:9::baseos | All versions | 0:2.4.0-12.el9_8 | | `kbd-debuginfo` | Red Hat:enterprise_linux:9::baseos | All versions | 0:2.4.0-12.el9_8 | | `kbd-debugsource` | Red Hat:enterprise_linux:9::baseos | All versions | 0:2.4.0-12.el9_8 | | `kbd-legacy` | Red Hat:enterprise_linux:9::baseos | All versions | 0:2.4.0-12.el9_8 | | `kbd-misc` | Red Hat:enterprise_linux:9::baseos | All versions | 0:2.4.0-12.el9_8 | | `kbd` | Red Hat:hummingbird:1 | All versions | 0:2.10.0-2.hum1 | | `kbd-legacy` | Red Hat:hummingbird:1 | All versions | 0:2.10.0-2.hum1 | | `kbd-misc` | Red Hat:hummingbird:1 | All versions | 0:2.10.0-2.hum1 | | `kbd` | Rocky Linux:10 | All versions | 0:2.6.4-8.el10_2 | | `kbd` | Rocky Linux:8 | All versions | 0:2.0.4-11.el8_10.1 | | `kbd` | Rocky Linux:9 | All versions | 0:2.4.0-12.el9_8 | | `kbd` | SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | All versions | 2.4.0-150400.5.12.1 | | `kbd` | SUSE:Linux Enterprise High Performance Computing 15 SP4-LTSS | All versions | 2.4.0-150400.5.12.1 | | `kbd` | SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | All versions | 2.4.0-150400.5.12.1 | | `kbd` | SUSE:Linux Enterprise High Performance Computing 15 SP5-LTSS | All versions | 2.4.0-150400.5.12.1 | | `kbd` | SUSE:Linux Enterprise Micro 5.3 | All versions | 2.4.0-150400.5.12.1 | | `kbd` | SUSE:Linux Enterprise Micro 5.4 | All versions | 2.4.0-150400.5.12.1 | | `kbd` | SUSE:Linux Enterprise Micro 5.5 | All versions | 2.4.0-150400.5.12.1 | | `kbd` | SUSE:Linux Enterprise Module for Basesystem 15 SP7 | All versions | 2.4.0-150700.15.10.1 | | `kbd` | SUSE:Linux Enterprise Server 15 SP4-LTSS | All versions | 2.4.0-150400.5.12.1 | | `kbd` | SUSE:Linux Enterprise Server 15 SP5-LTSS | All versions | 2.4.0-150400.5.12.1 | ## How do I fix CVE-2026-72693? Apply the vendor's patch. ## Is CVE-2026-72693 being exploited? There is no known exploitation of CVE-2026-72693 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-72693 and fix it if it is affected. What it is: CVE-2026-72693 is a high-severity vulnerability in Red Hat Enterprise Linux 10, published on 11 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-72693 in the wild and no public exploit code. Affected product: Red Hat Enterprise Linux 10. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-72693/ (Markdown: https://insights.sbomify.com/CVE-2026-72693/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72693 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72693 - OSV: https://osv.dev/vulnerability/CVE-2026-72693 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-72693/ Summaries are generated and may contain mistakes; the official description above is the record.