Joomla! CMS EUVD-2026-31879

Q: What is the CVSS score of EUVD-2026-31879?

EUVD-2026-31879 has a CVSS 4.0 base score of 6.4 (Medium). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:L/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.0%.

| CVE-2026-48900 MEDIUM

Improper Access Control (CWE-284)

2026-05-26 Joomla

GHSA-cwvc-2p7m-grcm

Authentication Bypass Joomla Cms

6.4

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

6.4 MEDIUM

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:L/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:L/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Lifecycle Timeline

Analysis Generated

Jun 08, 2026 - 11:12 vuln.today

CVSS changed

May 26, 2026 - 17:22 NVD

6.4 (MEDIUM)

CVE Published

May 26, 2026 - 16:43 nvd

UNKNOWN (no severity yet)

DescriptionCVE.org

An improper access check allowed low privileged users to edit the task types of existing scheduler tasks.

AnalysisAI

Improper access control in Joomla! CMS com_scheduler component permits low-privileged authenticated backend users to modify the task types of existing scheduler tasks, an operation that should be restricted to higher-privileged administrators. Affected versions span Joomla! 4.1.0 through 5.4.5 and 6.0.0 through 6.1.0. While no public exploit code exists and CISA KEV has not confirmed active exploitation, the high subsequent-system impact scores (SC:H/SI:H/SA:H) in the CVSS 4.0 vector indicate that tampering with scheduler task types can produce significant integrity and availability consequences beyond the immediately vulnerable component.

Technical ContextAI

The vulnerability resides in the com_scheduler component of the Joomla! CMS (CPE: cpe:2.3:a:joomla!_project:joomla!_cms:*:*:*:*:*:*:*:*), a built-in plugin that manages automated background tasks. The root cause is classified as CWE-284 (Improper Access Control), meaning the application fails to correctly enforce authorization boundaries when a backend user submits a request to change the task type of an already-existing scheduler job. Rather than verifying that the requesting user holds the appropriate ACL permission for that operation, the component processes the modification request regardless of privilege level. Because scheduler tasks in Joomla can invoke system-level plugins, file operations, or third-party integrations, unrestricted modification of task types exposes adjacent systems and services to unintended behavior - reflected in the CVSS 4.0 subsequent-system scores of SC:H/SI:H/SA:H.

RemediationAI

Apply the patched Joomla! CMS release identified in the official security advisory at https://developer.joomla.org/security-centre/1048-20260516-core-incorrect-access-control-in-com-scheduler.html - the exact fixed version numbers are not independently confirmed in the available intelligence data and should be verified there before upgrading. As a compensating control prior to patching, administrators can restrict backend login access to only fully trusted users via Joomla's ACL manager, reducing the pool of accounts capable of reaching the com_scheduler interface. Additionally, auditing existing scheduler tasks for unexpected task-type changes can serve as a detective control. Note that restricting backend access may affect legitimate editorial or content-management workflows and should be coordinated with site operators.