What is CVE-2026-48958?

CVE-2026-48958 is a high-severity vulnerability in Joomla Joomla\!, classified under Improper Access Control. CVSS score: 8.8/10. Published 2026-07-07.

How severe is CVE-2026-48958?

High severity. CVSS v3 base score is 8.8 out of 10.

Vulnerability in Joomla Joomla\!

CVE-2026-48958

An improper access check allows unauthorized users to create custom fields via webservices endpoints.

Published 2026-07-07 · last modified 2026-07-09.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (37.9th percentile), scored 2026-10-08.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 37.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Joomla Joomla\!
Joomla! Project Cms — versions 4.0.0-5.4.6, 6.0.0-6.1.1

Weakness classification (CWE)

CWE-284 — Improper Access Control

References

developer.joomla.org/security-centre/1066-20260712-core-incorrect-access-contro… (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2026-48958?: CVE-2026-48958 is a high-severity vulnerability in Joomla Joomla\!, classified under Improper Access Control. CVSS score: 8.8/10. Published 2026-07-07.
How severe is CVE-2026-48958?: High severity. CVSS v3 base score is 8.8 out of 10.