CVE-2026-41891
📛 CVE Title
CI4MS: Deactivated User Session Bypass (active=0)
Description
CI4MS is a CodeIgniter 4-based CMS skeleton that delivers a production-ready, modular architecture with RBAC authorization and theme support. From version 0.26.0 to before version 0.31.8.0, the auth filter has the deactivated/banned user check commented out. This issue has been patched in version 0.31.8.0.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- GitHub_M
- CVSS severity
- MEDIUM
- CVSS score
- 5.3 / 10
- CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N- Effective score
- 5.3 / 10 MEDIUM source: CNA overview
- CWE(s)
-
CWE-613 - Reserved
- 2026-04-22
- Published
- 2026-05-07 03:24 UTC
- Last updated
- 2026-05-07 12:47 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/41xxx/CVE-2026-41891.json
- Linked Threat
- CVE-2026-41891 — CVE-2026-41891
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-05-07 04:16:33 UTC
- NVD last modified
- 2026-05-07 14:57:13 UTC
- EPSS score
- 0.0001 (probability of exploitation in next 30 days)
- EPSS percentile
- 2.99% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24
NVD / KEV / EPSS data refreshed 2026-05-25 02:13 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
European Union Vulnerability Database ENISA EUVD
ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.
- EUVD ID
-
EUVD-2026-28294 - Assigner
- GitHub_M
- Published
- May 7, 2026, 3:24:43 AM
- Updated
- May 7, 2026, 12:47:44 PM
- EUVD base score (CVSS 4.0)
-
5.3 / 10
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N - EUVD-reported EPSS
- 0.0100
- Vendors
- ci4-cms-erp
- Products
-
ci4ms (0.26.0, < 0.31.8.0)
- Aliases
-
GHSA-5hfv-c864-qcq9
ENISA description: CI4MS is a CodeIgniter 4-based CMS skeleton that delivers a production-ready, modular architecture with RBAC authorization and theme support. From version 0.26.0 to before version 0.31.8.0, the auth filter has the deactivated/banned user check commented out. This issue has been patched in version 0.31.8.0.
Affected products (1)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| ci4-cms-erp | ci4ms |
>= 0.26.0, < 0.31.8.0 (affected)
|
— |
Vendor references (2)
References embedded in the original CVE record by the assigning CNA.
- https://github.com/ci4-cms-erp/ci4ms/security/advisories/GHSA-5hfv-c864-qcq9 x_refsource_CONFIRM
- https://github.com/ci4-cms-erp/ci4ms/releases/tag/0.31.8.0 x_refsource_MISC
Web references (5)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
- https://github.com/ci4-cms-erp/ci4ms/releases/tag/0.31.8.0 tenable:github.com
- https://github.com/ci4-cms-erp/ci4ms/security/advisories/GHSA-5hfv-c864-qcq9 tenable:github.com
- https://nvd.nist.gov/vuln/detail/CVE-2026-41891 tenable:nvd.nist.gov
- https://www.cve.org/CVERecord?id=CVE-2026-41891 tenable:www.cve.org
- https://www.first.org/epss/ tenable:www.first.org
NVD-tagged references (2)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- https://github.com/ci4-cms-erp/ci4ms/releases/tag/0.31.8.0 security-advisories@github.com
- https://github.com/ci4-cms-erp/ci4ms/security/advisories/GHSA-5hfv-c864-qcq9 security-advisories@github.com
Remediations (15)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:app.opencve.io
Remediation No vendor fix or workaround currently provided. OpenCVE Recommended Actions Install the latest security update for Microsoft Defender from the Microsoft Security Response Center (see https://msrc.microsoft.com/update-guide/vulnerability/ CVE - 2026 -41091).
2026-05-23 21:53 UTC -
web:blog.gridinsoft.com
Microsoft has confirmed exploitation of two Microsoft Defender vulnerabilities fixed in the May 2026 security update cycle. CVE - 2026 -41091 is an elevation-of-privilege flaw in the Microsoft Malware Protection Engine, while CVE - 2026 -45498 is a denial-of-service flaw in the Microsoft Defender Antimalware Platform . The first bug matters more for incident response because a local authorized ...
2026-05-23 21:53 UTC -
web:cyberpress.org
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added two actively exploited Microsoft Defender vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, issuing an urgent remediation directive for federal agencies with a due date of June 3, 2026 .
2026-05-23 21:53 UTC -
web:nvd.nist.gov
An official website of the United States government NVD MENU
2026-05-23 21:53 UTC -
web:portal.msrc.microsoft.com
The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.
2026-05-23 21:53 UTC -
web:purple-ops.io
Remediation for CVE - 2026 -41091 and CVE - 2026 -45498 involves updating the Microsoft Malware Protection Engine and the Microsoft Defender Antimalware Platform to the patched versions.
2026-05-23 21:53 UTC -
web:thecyberexpress.com
Microsoft confirms active exploitation of CVE - 2026 -41091 and CVE - 2026 -45498 in Defender, with CVSS-rated risks, KEV listing, and urgent patches issued.
2026-05-23 21:53 UTC -
web:www.csoonline.com
Microsoft released emergency fixes for two zero-day vulnerabilities in the malware protection components of Microsoft Defender. The flaws allow local attackers to gain system-level privileges or ...
2026-05-23 21:53 UTC -
web:www.forbes.com
Microsoft has confirmed an emergency security update as CISA warns that two new Defender zero-days are being exploited by attackers.
2026-05-23 21:53 UTC -
web:www.techradar.com
CISA confirms two bugs being actively exploited in the wild, as Microsoft releases patches.
2026-05-23 21:53 UTC -
web:cybersecurefox.com
Given the confirmed active exploitation and the CISA deadline of June 3, 2026 , remediation of CVE - 2026 -41091 should be treated as critical —immediate verification and updating of all systems with active Microsoft Defender, with special attention to servers and workstations that have access to sensitive data or privileged accounts.
2026-05-26 02:48 UTC -
web:cybersecuritynews.com
Two newly disclosed Microsoft Defender vulnerabilities are being actively exploited in the wild, enabling local attackers to elevate privileges to SYSTEM and potentially disrupt endpoint protection across Windows environments.
2026-05-26 02:48 UTC -
web:howtofix.guide
CISA added both CVE - 2026 -41091 and CVE - 2026 -45498 to its Known Exploited Vulnerabilities catalog on May 20, with a federal remediation due date of June 3, 2026 . [4] That KEV entry does not mean every home PC is currently targeted, but it is a clear signal that defenders should not wait for the next normal maintenance window.
2026-05-26 02:48 UTC -
web:thehackernews.com
Microsoft has disclosed that a privilege escalation and a denial-of-service flaw in Defender has come under active exploitation in the wild. The former, tracked as CVE - 2026 -41091, is rated 7.8 on the CVSS scoring system. Successful exploitation of the flaw could allow an attacker to gain SYSTEM privileges. "Improper link resolution before file access ('link following') in Microsoft Defender ...
2026-05-26 02:48 UTC -
web:www.microsoft.com
Security Update Guide Notifications Microsoft's free Security Update Guide Notifications provide links to security-related software updates and notification of re-released security updates. These notifications are sent via email throughout the month as needed.
2026-05-26 02:48 UTC
AI Forensic Analysis
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-41891.json.
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