Joomla! CMS CVE-2026-48899

Q: What is the CVSS score of CVE-2026-48899?

CVE-2026-48899 has a CVSS 4.0 base score of 5.3 (Medium). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/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%.

EUVD-2026-31880 MEDIUM

Improper Access Control (CWE-284)

2026-05-26 Joomla

GHSA-rfwr-f8vm-98cv

Authentication Bypass Privilege Escalation Joomla Cms

5.3

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

5.3 MEDIUM

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/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:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/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

Low

User Interaction

None

Scope

Lifecycle Timeline

Analysis Generated

Jun 08, 2026 - 11:11 vuln.today

CVSS changed

May 26, 2026 - 17:22 NVD

5.3 (MEDIUM)

CVE Published

May 26, 2026 - 16:44 nvd

UNKNOWN (no severity yet)

DescriptionCVE.org

An improper access check allows privilege escalation through the com_users batch task.

AnalysisAI

Privilege escalation in Joomla! CMS via the com_users batch task allows low-privileged authenticated users to bypass access controls and elevate their user group membership or permissions. Affected versions span two major release lines: 4.0.0 through 5.4.5 and 6.0.0 through 6.1.0, as confirmed by ENISA EUVD-2026-31880 and the Joomla Security Centre. No public exploit has been identified and EPSS is effectively zero; however, SSVC assesses the technical impact as total, meaning successful exploitation could yield full privilege takeover within the application.

Technical ContextAI

Joomla! CMS is a widely-deployed PHP-based content management system. The vulnerability resides in the com_users component, specifically its batch processing task, which handles bulk operations on user accounts such as group assignment changes. CWE-284 (Improper Access Control) indicates the batch task endpoint fails to correctly verify whether the requesting authenticated user holds the necessary privileges to execute those operations - allowing a lower-privileged user to invoke functionality reserved for administrators. The affected CPE is cpe:2.3:a:joomla!_project:joomla!_cms:*:*:*:*:*:*:*:* spanning both the 4.x/5.x and 6.x release lines. The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:L/UI:N) confirms remote exploitability with low complexity and no user interaction, requiring only low-level authentication.

RemediationAI

Upgrade Joomla! CMS to a release above 5.4.5 (for the 4.x/5.x line) or above 6.1.0 (for the 6.x line) per the Joomla Security Centre advisory at https://developer.joomla.org/security-centre/1047-20260515-core-incorrect-access-control-in-sample-data-plugins.html. The precise patched version numbers are not independently confirmed in available data beyond the stated affected ranges - consult the official advisory and Joomla release notes for the exact target upgrade version. As a compensating control prior to patching, use Joomla's built-in ACL manager to explicitly deny the com_users batch task permission from all non-administrator user groups; be aware this may restrict legitimate bulk user management workflows for lower-level managers. Additionally, disabling public user registration reduces the pool of potential attackers to already-known accounts, providing a meaningful reduction in attack surface without disrupting existing authenticated users.