CVE-2026-96512

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

HIGH
7.8
CVSS Score
Published: September 23, 2026 at 01:22 PM UTC
Updated: October 29, 2026 at 08:17 PM UTC
1 product affected across 1 vendorEnterprise Linux

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Severity
HIGH7.8
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versions7
Vendor states this is fixed in 0:1.9.15-8.p5.el10_0.5 (unaffected)
Vendor states this is fixed in 0:1.9.17-10.p2.el10_2.7 (unaffected)
Vendor states this is fixed in 0:1.9.17p2-3.el9_8.3 (unaffected)
Vendor states this is fixed in 0:1.9.5p2-1.el8_8.4 (unaffected)
Vendor states this is fixed in 0:1.9.5p2-10.el9_4.4 (unaffected)
Vendor states this is fixed in 0:1.9.5p2-10.el9_6.4 (unaffected)
Vendor states this is fixed in 0:1.9.5p2-2.el8_10 (unaffected)

References (20)

Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:71609
Source: af854a3a-2127-422b-91ae-364da2661108
http://www.openwall.com/lists/oss-security/2026/09/24/4
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:75580
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:75579
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:75571

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.8HIGHredhat
Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-863

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