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TI-2026-50931 Aliases CVE-2026-72693GHSA-6766-cx7r-c5q6

Kbd: local privilege escalation in openvt via incorrect process owner verification allowing passwordless root login

Priority LOW 35CWE-284Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 5 fixed, 4 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-284.

Summary

`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/<pid>/fd/0")`. `stat()` on `/proc/<pid>/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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00148 3rd percentileScored 2026-11-07
Fix Partial Red Hat: 6 advisoriesRed Hat: 5 fixed, 4 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Red HatRed Hat Enterprise Linux 10—2.6.4-8.el10_2Patch availableCNA
Red HatRed Hat Enterprise Linux 8—2.0.4-11.el8_10.1Patch availableCNA
Red HatRed Hat Enterprise Linux 9—2.4.0-12.el9_8Patch availableCNA
Red HatRed Hat OpenShift Container Platform 4.22—4.22.9.8.202608251819-0Patch availableCNA
Red HatRed Hat OpenShift Container Platform 4.22—4.22.9.8.202609081748-0Patch availableCNA
Red HatRed Hat Hardened Images—2.10.0-2.hum1Patch availableCNA
Red HatRed Hat Enterprise Linux 6——No fix listedCNA
Red HatRed Hat Enterprise Linux 7——No fix listedCNA
Red HatRed Hat OpenShift Container Platform 4——No fix listedCNA
Red HatRed Hat OpenShift Container Platform 5——No fix listedCNA
  • Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in 2.6.4-8.el10_2 Patch available CNA
  • Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in 2.0.4-11.el8_10.1 Patch available CNA
  • Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in 2.4.0-12.el9_8 Patch available CNA
  • Red Hat OpenShift Container Platform 4.22 VendorRed Hat Affected — Fixed in 4.22.9.8.202608251819-0 Patch available CNA
  • Red Hat OpenShift Container Platform 4.22 VendorRed Hat Affected — Fixed in 4.22.9.8.202609081748-0 Patch available CNA
  • Red Hat Hardened Images VendorRed Hat Affected — Fixed in 2.10.0-2.hum1 Patch available CNA
  • Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — No fix listed CNA
  • Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — No fix listed CNA
  • Red Hat OpenShift Container Platform 4 VendorRed Hat Affected — Fixed in — No fix listed CNA
  • Red Hat OpenShift Container Platform 5 VendorRed Hat Affected — Fixed in — No fix listed CNA

CPE names CNA · 9

CPEVersionsRoleVendor
cpe:/o:redhat:enterprise_linux:10.210.2—Red Hat
cpe:/o:redhat:enterprise_linux:8::baseos8—Red Hat
cpe:/o:redhat:enterprise_linux:9::baseos9—Red Hat
cpe:/a:redhat:openshift:4.22::el94.22—Red Hat
cpe:/a:redhat:hummingbird:11—Red Hat
cpe:/o:redhat:rhel_els:66—Red Hat
cpe:/o:redhat:rhel_els:77—Red Hat
cpe:/a:redhat:openshift:44—Red Hat
cpe:/a:redhat:openshift:55—Red Hat
  • cpe:/o:redhat:enterprise_linux:10.2 Versions 10.2 — ·Red Hat
  • cpe:/o:redhat:enterprise_linux:8::baseos Versions 8 — ·Red Hat
  • cpe:/o:redhat:enterprise_linux:9::baseos Versions 9 — ·Red Hat
  • cpe:/a:redhat:openshift:4.22::el9 Versions 4.22 — ·Red Hat
  • cpe:/a:redhat:hummingbird:1 Versions 1 — ·Red Hat
  • cpe:/o:redhat:rhel_els:6 Versions 6 — ·Red Hat
  • cpe:/o:redhat:rhel_els:7 Versions 7 — ·Red Hat
  • cpe:/a:redhat:openshift:4 Versions 4 — ·Red Hat
  • cpe:/a:redhat:openshift:5 Versions 5 — ·Red Hat

Remediation

Red Hat 6 advisories

  • RHSA-2026:78951 Released 2026-10-08 · Red Hat rating Moderate
    kbd security update
    • Red Hat Enterprise Linux BaseOS (v. 8) kbd-2.0.4-11.el8_10.1, kbd-legacy-2.0.4-11.el8_10.1, kbd-misc-2.0.4-11.el8_10.1
  • RHSA-2026:66357 Released 2026-09-15 · Red Hat rating Important
    OpenShift Container Platform 4.22.14 bug fix and security update
    • Red Hat OpenShift Container Platform 4.22 rhcos-aarch64-4.22.9.8.202609081748-0, rhcos-ppc64le-4.22.9.8.202609081748-0, rhcos-s390x-4.22.9.8.202609081748-0 +1
  • RHSA-2026:60440 Released 2026-09-01 · Red Hat rating Important
    OpenShift Container Platform 4.22.12 bug fix and security update
    • Red Hat OpenShift Container Platform 4.22 rhcos-aarch64-4.22.9.8.202608251819-0, rhcos-ppc64le-4.22.9.8.202608251819-0, rhcos-s390x-4.22.9.8.202608251819-0 +1
Show 3 more Red Hat advisories
  • RHSA-2026:57610 Released 2026-08-20 · Red Hat rating Moderate
    kbd security update
    • Red Hat Enterprise Linux BaseOS (v. 9) kbd-2.4.0-12.el9_8, kbd-legacy-2.4.0-12.el9_8, kbd-misc-2.4.0-12.el9_8
  • RHSA-2026:57597 Released 2026-08-20 · Red Hat rating Moderate
    kbd security update
    • Red Hat Enterprise Linux BaseOS (v. 10) kbd-2.6.4-8.el10_2, kbd-legacy-2.6.4-8.el10_2, kbd-misc-2.6.4-8.el10_2
  • RHSA-2026:41136 Released 2026-07-16 · Red Hat rating Moderate
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images kbd-2.10.0-2.hum1@aarch64, kbd-2.10.0-2.hum1@src, kbd-2.10.0-2.hum1@x86_64 +4

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

    Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8 and 4 more products — RHSA-2026:60440

    2 records Highest priority Priority LOW 2 LOW

    Other records, highest priority first

    • TI-2026-13304 Dracut: dracut: root code execution via unescaped error message written to sourced emergency hook script in die()Priority LOW 35
    Show all 2 records → Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix yet
Red Hat OpenShift Container Platform 4AffectedNo fix yet
Red Hat OpenShift Container Platform 5AffectedNo fix yet
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:57597
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2026:78951
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:57610
Red Hat Hardened ImagesFixed RHSA-2026:41136
Red Hat OpenShift Container Platform 4.22Fixed RHSA-2026:60440, RHSA-2026:66357

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-72693
  2. 2026-10-03 Alias added: GHSA-6766-cx7r-c5q6
  3. 2026-10-09 Fix available: RHSA-2026:78951 · Red Hat
  4. 2026-10-09 Fix available: Red Hat Enterprise Linux BaseOS (v. 8) · Red Hat
  5. 2026-10-09 Fix available: kbd@0:2.0.4-11.el8_10.1, openshift/[email protected], openshift/[email protected] · CNA
  6. 2026-10-09 1 new reference · CNA
  7. 2026-11-02 Affected versions changed · CNA
  8. 2026-11-02 Affected versions changed · Red Hat

References

Advisory 6

Other 2

  • TI-2019-15875 Protection mechanism failure in Jenkins Pipeline: Groovy Plugin KEVCVSS 3.1CRITICAL 9.9
  • TI-2019-15874 Protection mechanism failure in Jenkins Script Security Plugin KEVCVSS 3.1CRITICAL 9.9
  • TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
  • TI-2019-05363 Code injection in Elastic Kibana KEVCVSS 3.1CRITICAL 10.0
  • TI-2019-03949 Out-of-bounds write in ESXi and Horizon DaaS KEVCVSS 3.1CRITICAL 9.8
  • TI-2018-16080 A code execution vulnerability exists in the Stapler web framework used by Jenkins 2.153… KEVCVSS 3.1CRITICAL 9.8
See all 7413 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences