CVE-2026-96512Sudo: sudo: tz environment variable allows bypass of notbefore/notafter time-based authorization

Description

A flaw was found in sudo. When sudoers rules use NOTBEFORE or NOTAFTER time-based access restrictions with timestamps that omit the trailing 'Z' timezone indicator, the time evaluation relies on the TZ environment variable inherited from the calling user. Because sudo is a setuid-root program, an unprivileged local user can set TZ to an extreme timezone offset to shift the authorization window by up to approximately 25 hours, causing expired rules to be treated as valid. This allows the user to execute commands outside the intended time window. Authentication is not bypassed; only the time-based authorization check is affected.

Timeline

Scores

EPSS (exploitation in 30 days)

0.32% · top 75% of all CVEs (14 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: total

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.

Affected products

• Red Hat · Red Hat Enterprise Linux 10

  • unaffected 0:1.9.17-10.p2.el10_2.7 – < *

• Red Hat · Red Hat Enterprise Linux 10.0 Extended Update Support

  • unaffected 0:1.9.15-8.p5.el10_0.5 – < *

• Red Hat · Red Hat Enterprise Linux 7 Extended Lifecycle Support

  • unaffected 0:1.8.23-10.el7_9.6 – < *

• Red Hat · Red Hat Enterprise Linux 8

  • unaffected 0:1.9.5p2-2.el8_10 – < *

• Red Hat · Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support

  • unaffected 0:1.8.29-7.el8_4.4 – < *

• Red Hat · Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

  • unaffected 0:1.8.29-7.el8_4.4 – < *

• Red Hat · Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support

  • unaffected 0:1.9.5p2-1.el8_6.4 – < *

• Red Hat · Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On

  • unaffected 0:1.9.5p2-1.el8_6.4 – < *

• Red Hat · Red Hat Enterprise Linux 8.8 Telecommunications Update Service

  • unaffected 0:1.9.5p2-1.el8_8.4 – < *

• Red Hat · Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions

  • unaffected 0:1.9.5p2-1.el8_8.4 – < *

• Red Hat · Red Hat Enterprise Linux 9

  • unaffected 0:1.9.17p2-3.el9_8.3 – < *

• Red Hat · Red Hat Enterprise Linux 9

  • unaffected 0:1.9.17p2-3.el9_8.3 – < *

• Red Hat · Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

  • unaffected 0:1.9.5p2-9.el9_2.5 – < *

• Red Hat · Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions

  • unaffected 0:1.9.5p2-10.el9_4.4 – < *

• Red Hat · Red Hat Enterprise Linux 9.6 Extended Update Support

  • unaffected 0:1.9.5p2-10.el9_6.4 – < *

• Red Hat · Red Hat Hardened Images

  • unaffected 1.9.17-16.p2.2.hum1 – < *

• Red Hat · Red Hat OpenShift AI 3.0

  • unaffected 1793041981 – < *

• Red Hat · Red Hat OpenShift AI 3.4

  • unaffected 1793042006 – < *

• Red Hat · Red Hat OpenShift AI 3.4

  • unaffected 1793041995 – < *

• Red Hat · Red Hat Update Infrastructure 5

  • unaffected 1791964013 – < *

• Red Hat · Red Hat Update Infrastructure 5

  • unaffected 1791978693 – < *

What to do

Workaround: Append the 'Z' timezone suffix to all NOTBEFORE and NOTAFTER timestamps in sudoers rules. For example, change 'NOTAFTER=20261231235959' to 'NOTAFTER=20261231235959Z'. Timestamps with the 'Z' suffix are interpreted as UTC via timegm() and are not affected by the TZ environment variable. Administrators can audit their sudoers configuration with: grep -rE 'NOT(BEFORE|AFTER)=' /etc/sudoers /etc/sudoers.d/ and verify that all timestamps end with 'Z'.

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2026-85290 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-96512](https://cveledger.app/badge/CVE-2026-96512.svg)](https://cveledger.app/cve/CVE-2026-96512)

Record last updated 29 Oct 2026, 19:53 UTC.