Sudo: sudo: tz environment variable allows bypass of notbefore/notafter time-based authorization (CVE-2026-96512)
Published Last modified Sources: Red Hat, BSI, CVE.org, Ubuntu, Msrc Update Guide
What is affected, what to do
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.
An exploit is publicly available. Update Red Hat Enterprise Linux 10 to version 0:1.9.17-10.p2.el10_2.7, Red Hat Enterprise Linux 10.0 Extended Update Support to version 0:1.9.15-8.p5.el10_0.5, Red Hat Enterprise Linux 7 Extended Lifecycle Support to version 0:1.8.23-10.el7_9.6.
- Affected
- Red Hat Enterprise Linux 10
lt *..0:1.9.17-10.p2.el10_2.7 - Red Hat Enterprise Linux 10.0 Extended Update Support
lt *..0:1.9.15-8.p5.el10_0.5 - Red Hat Enterprise Linux 7 Extended Lifecycle Support
lt *..0:1.8.23-10.el7_9.6 - Red Hat Enterprise Linux 8
lt *..0:1.9.5p2-2.el8_10 - Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
lt *..0:1.8.29-7.el8_4.4 - Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
lt *..0:1.8.29-7.el8_4.4 - Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
lt *..0:1.9.5p2-1.el8_6.4 - Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On
lt *..0:1.9.5p2-1.el8_6.4 - Red Hat Enterprise Linux 8.8 Telecommunications Update Service
lt *..0:1.9.5p2-1.el8_8.4 - Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
lt *..0:1.9.5p2-1.el8_8.4 - Red Hat Enterprise Linux 9
lt *..0:1.9.17p2-3.el9_8.3 - Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions
lt *..0:1.9.5p2-9.el9_2.5 - Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions
lt *..0:1.9.5p2-10.el9_4.4 - Red Hat Enterprise Linux 9.6 Extended Update Support
lt *..0:1.9.5p2-10.el9_6.4 - Red Hat Hardened Images
lt *..1.9.17-16.p2.2.hum1 - Red Hat OpenShift AI 3.0
lt *..1793041981 - Red Hat OpenShift AI 3.4
lt *..1793042006 - Red Hat OpenShift AI 3.4
lt *..1793041995 - Red Hat Update Infrastructure 5
lt *..1791964013 - Red Hat Update Infrastructure 5
lt *..1791978693
- Red Hat Enterprise Linux 10
- Fixed in
- Red Hat Enterprise Linux 10
0:1.9.17-10.p2.el10_2.7 - Red Hat Enterprise Linux 10.0 Extended Update Support
0:1.9.15-8.p5.el10_0.5 - Red Hat Enterprise Linux 7 Extended Lifecycle Support
0:1.8.23-10.el7_9.6 - Red Hat Enterprise Linux 8
0:1.9.5p2-2.el8_10 - Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
0:1.8.29-7.el8_4.4 - Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
0:1.8.29-7.el8_4.4 - Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
0:1.9.5p2-1.el8_6.4 - Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On
0:1.9.5p2-1.el8_6.4 - Red Hat Enterprise Linux 8.8 Telecommunications Update Service
0:1.9.5p2-1.el8_8.4 - Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
0:1.9.5p2-1.el8_8.4 - Red Hat Enterprise Linux 9
0:1.9.17p2-3.el9_8.3 - Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions
0:1.9.5p2-9.el9_2.5 - Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions
0:1.9.5p2-10.el9_4.4 - Red Hat Enterprise Linux 9.6 Extended Update Support
0:1.9.5p2-10.el9_6.4 - Red Hat Hardened Images
1.9.17-16.p2.2.hum1 - Red Hat OpenShift AI 3.0
1793041981 - Red Hat OpenShift AI 3.4
1793042006 - Red Hat OpenShift AI 3.4
1793041995 - Red Hat Update Infrastructure 5
1791964013 - Red Hat Update Infrastructure 5
1791978693
- Red Hat Enterprise Linux 10
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Metrics
7.8
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: NVD, CVSS v3
7.8
CVSS v3
Severity High on the scale from 0 to 10.
Source: Red Hat, BSI, CVE.org, Ubuntu, Msrc Update Guide
0.3 %
EPSS score
Low — model estimates < 1% exploitation likelihood.
Source: FIRST EPSS, percentile 25.1
Show all metrics
- Severity
- High
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 72.17 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- PoC (publicly reported)
XIEM Effective CVSS
XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.
Read in glossary- 7.8 Methodology
CVSS v3
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 7.8
EPSS score
The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.
Read in glossary- 0.3 %
- Low — model estimates < 1% exploitation likelihood.
EPSS percentile
The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.
Read in glossary- 25.1
- Elevated — this CVE ranks above at least 10% of all CVEs scored today.
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- —
- Published
- CISA assessment (SSVC)
- Exploitation: none known · not automatable · Technical impact: total
- Source: CISA Vulnrichment, as of 23 September 2026
CWE
CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.
Read in glossary- CWE-863
Detection rules
No NEOSEC detection rule is available for this vulnerability yet.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
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.
Source: redhat_csaf, BSI WID Portal, BSI CSAF, cvelistv5, Ubuntu Security Notices, NVD (NIST), Microsoft Security Update Guide
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Affected versions | Fixed in | ||
|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 |
|
|
| Red Hat | Red Hat Enterprise Linux 10.0 Extended Update Support |
|
|
| Red Hat | Red Hat Enterprise Linux 7 Extended Lifecycle Support |
|
|
| Red Hat | Red Hat Enterprise Linux 8 |
|
|
| Red Hat | Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support |
|
|
| Red Hat | Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On |
|
|
| Red Hat | Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support |
|
|
| Red Hat | Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On |
|
|
| Red Hat | Red Hat Enterprise Linux 8.8 Telecommunications Update Service |
|
|
| Red Hat | Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions |
|
|
| Red Hat | Red Hat Enterprise Linux 9 |
|
|
| Red Hat | Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions |
|
|
| Red Hat | Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions |
|
|
| Red Hat | Red Hat Enterprise Linux 9.6 Extended Update Support |
|
|
| Red Hat | Red Hat Hardened Images |
|
|
| Red Hat | Red Hat OpenShift AI 3.0 |
|
|
| Red Hat | Red Hat OpenShift AI 3.4 |
|
|
| Red Hat | Red Hat Update Infrastructure 5 |
|
|
Vendors and products
- Red Hat Red Hat Enterprise Linux 10
- Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support
- Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support
- Red Hat Red Hat Enterprise Linux 8
- Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
- Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-life Add-on
- Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
- Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-life Add-on
- Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service
- Red Hat Red Hat Enterprise Linux 8.8 Update Services For Sap Solutions
- Red Hat Red Hat Enterprise Linux 9
- Red Hat Red Hat Enterprise Linux 9.2 Update Services For Sap Solutions
Affected operating systems
| Linux | ubuntu | sudo | jammy |
| Linux | ubuntu | sudo | noble |
| Linux | ubuntu | sudo | resolute |
Weakness classes (CWE)
CWE-863Incorrect Authorization
Class
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
Entry at MITRE CWE-863
Public exploit references
Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.
| PoC-in-GitHub (nomi-sec) | CVE-2026-96512 (opens in a new tab)github.com | PoC (publicly reported)reported, not verified |
References & sources
- access.redhat.comsecurity/cve/CVE-2026-96512Vulnerability database, x_refsource_REDHAT
- bugzilla.redhat.comRHBZ#2539327Issue tracking, x_refsource_REDHAT
- github.comsudo-project/sudo/commit/1820a349687522f51023d1ae5925125f59679a…
- access.redhat.comRHSA-2026:71609Vendor advisory, x_refsource_REDHAT
- openwall.comlists/oss-security/2026/09/24/4
- access.redhat.comRHSA-2026:75580Vendor advisory, x_refsource_REDHAT
- access.redhat.comRHSA-2026:75579Vendor advisory, x_refsource_REDHAT
- access.redhat.comRHSA-2026:75571Vendor advisory, x_refsource_REDHAT
- access.redhat.comRHSA-2026:82939Vendor advisory, x_refsource_REDHAT
- access.redhat.comRHSA-2026:86634Vendor advisory, x_refsource_REDHAT
- access.redhat.comRHSA-2026:86635Vendor advisory, x_refsource_REDHAT
- access.redhat.comRHSA-2026:87026Vendor advisory, x_refsource_REDHAT
- access.redhat.comRHSA-2026:86633Vendor advisory, x_refsource_REDHAT
- access.redhat.comRHSA-2026:90287Vendor advisory, x_refsource_REDHAT
- access.redhat.comRHSA-2026:92325Vendor advisory, x_refsource_REDHAT
- access.redhat.comRHSA-2026:92349Vendor advisory, x_refsource_REDHAT
- access.redhat.comRHSA-2026:92326Vendor advisory, x_refsource_REDHAT
- access.redhat.comRHSA-2026:91217Vendor advisory, x_refsource_REDHAT
- access.redhat.comRHSA-2026:91219Vendor advisory, x_refsource_REDHAT
- access.redhat.comRHSA-2026:91244Vendor advisory, x_refsource_REDHAT
Changes to this CVE
Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).
Record modifiedRed Hat
Show 4 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/96xxx/CVE-2026-96512.json">CVE-2026-96512</a>Reference added —https://access.redhat.com/errata/RHSA-2026:91217Reference added —https://access.redhat.com/errata/RHSA-2026:91219Reference added —https://access.redhat.com/errata/RHSA-2026:91244Source identifier: secalert@redhat.com
Record modifiedRed Hat
New references:Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/96xxx/CVE-2026-96512.json">CVE-2026-96512</a>Reference added —https://access.redhat.com/errata/RHSA-2026:92326Source identifier: secalert@redhat.com
Record modifiedRed Hat
New references:Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/96xxx/CVE-2026-96512.json">CVE-2026-96512</a>Reference added —https://access.redhat.com/errata/RHSA-2026:92349Source identifier: secalert@redhat.com
Record modifiedRed Hat
New references:Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/96xxx/CVE-2026-96512.json">CVE-2026-96512</a>Reference added —https://access.redhat.com/errata/RHSA-2026:92325Source identifier: secalert@redhat.com
Record modifiedRed Hat
New references:Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/96xxx/CVE-2026-96512.json">CVE-2026-96512</a>Reference added —https://access.redhat.com/errata/RHSA-2026:90287Source identifier: secalert@redhat.com
Show 13 older changes
Record modifiedRed Hat
New references:Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/96xxx/CVE-2026-96512.json">CVE-2026-96512</a>Reference added —https://access.redhat.com/errata/RHSA-2026:86633Source identifier: secalert@redhat.com
Record modifiedRed Hat
New references:Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/96xxx/CVE-2026-96512.json">CVE-2026-96512</a>Reference added —https://access.redhat.com/errata/RHSA-2026:86635Source identifier: secalert@redhat.com
Record modifiedRed Hat
New references:Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/96xxx/CVE-2026-96512.json">CVE-2026-96512</a>Reference added —https://access.redhat.com/errata/RHSA-2026:86634Source identifier: secalert@redhat.com
Record modifiedRed Hat
New references:Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/96xxx/CVE-2026-96512.json">CVE-2026-96512</a>Reference added —https://access.redhat.com/errata/RHSA-2026:82939Source identifier: secalert@redhat.com
Record modifiedRed Hat
New references:Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/96xxx/CVE-2026-96512.json">CVE-2026-96512</a>Reference added —https://access.redhat.com/errata/RHSA-2026:75571Source identifier: secalert@redhat.com
Record modifiedRed Hat
New references:Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/96xxx/CVE-2026-96512.json">CVE-2026-96512</a>Reference added —https://access.redhat.com/errata/RHSA-2026:75579Source identifier: secalert@redhat.com
Record modifiedRed Hat
New references:Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/96xxx/CVE-2026-96512.json">CVE-2026-96512</a>Reference added —https://access.redhat.com/errata/RHSA-2026:75580Source identifier: secalert@redhat.com
Record modifiedCVE Program
New references:Show the original change
Individual changes of this event as published by NVD Type Action Before After Reference added —http://www.openwall.com/lists/oss-security/2026/09/24/4Source identifier: af854a3a-2127-422b-91ae-364da2661108
Record modifiedRed Hat
New references:Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/96xxx/CVE-2026-96512.json">CVE-2026-96512</a>Reference added —https://access.redhat.com/errata/RHSA-2026:71609Source identifier: secalert@redhat.com
Record modifiedCISA ADP
CISA assessment (SSVC): exploitation: none known, automatable: no
Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After SSVC assessment removed {"id":"CVE-2026-96512","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-09-23T16:18:10.918476Z"}—SSVC assessment added —{"id":"CVE-2026-96512","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-09-23T00:00:00+00:00"}Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Record modifiedCISA ADP
CISA assessment (SSVC): exploitation: none known, automatable: no
Show the original change
Individual changes of this event as published by NVD Type Action Before After SSVC assessment added —{"id":"CVE-2026-96512","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-09-23T16:18:10.918476Z"}Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Record modifiedRed Hat
1 individual change: Affected versions (publisher)
Show the original change
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/96xxx/CVE-2026-96512.json">CVE-2026-96512</a>Source identifier: secalert@redhat.com
ReceivedRed Hat
CVSS V3.1: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness type: CWE-863
Description added or changed
Show 7 original changes
Individual changes of this event as published by NVD Type Action Before After Description added —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.CVSS added —AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HWeakness type (CWE) added —CWE-863Affected versions (publisher) added —New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/96xxx/CVE-2026-96512.json">CVE-2026-96512</a>Reference added —https://access.redhat.com/security/cve/CVE-2026-96512Reference added —https://bugzilla.redhat.com/show_bug.cgi?id=2539327Reference added —https://github.com/sudo-project/sudo/commit/1820a349687522f51023d1ae5925125f59679a8cSource identifier: secalert@redhat.com
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