CVE-2026-48958Network attack vector

Unauthorized custom-field creation via improper access check

Published Jul 7, 2026 · Updated Jul 7, 2026

Improper access control in Joomla! CMS 4.0.0 through 5.4.6 and 6.0.0 through 6.1.1 allows remote authenticated users to create custom fields. The com_fields webservice endpoints perform an improper access check before accepting custom-field creation requests; Joomla has not disclosed the code locus. A highly privileged account and network access are required; the operation changes CMS field configuration, with no direct data read or service interruption reported.

CVSS severity6.4
Medium
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in Joomla! CMS 4.0.0 through 5.4.6 and 6.0.0 through 6.1.1 allows remote authenticated users to create custom fields. The com_fields webservice endpoints perform an improper access check before accepting custom-field creation requests; Joomla has not disclosed the code locus. A highly privileged account and network access are required; the operation changes CMS field configuration, with no direct data read or service interruption reported.

The record

CVE
CVE-2026-48958
Published
Jul 7, 2026
Updated
Jul 7, 2026
Vendor
Joomla! Project
Product
Joomla! CMS
Classifications
CWE-284, CAPEC-1, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 7, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.0.0-5.4.6
  2. Affected versionversion=6.0.0-6.1.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Joomla! Project · Joomla! CMSversion=4.0.0-5.4.6; version=6.0.0-6.1.1

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
6.4Joomla! ProjectCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:N/SC:H/SI:H/SA:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
CAPEC-1Accessing Functionality Not Properly Constrained by ACLs
T1565.001Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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