Security Announcements

• [20260520] - Framework - Inadequate content filtering within the cleanAttributes filter code

  • Project: Joomla!
  • SubProject: Framewok
  • Impact: Moderate
  • Severity: Moderate
  • Probability: Moderate
  • Versions: 3.0.0-5.4.5,6.0.0-6.1.0
  • Exploit type: XSS
  • Reported Date: 2026-05-04
  • Fixed Date: 2026-05-26
  • CVE Number: CVE-2026-48905

  Description

  Lack of input filtering leads to an XSS vector in the HTML filter code.

  Affected Installs

  Joomla! CMS versions 3.0.0-5.4.5,6.0.0-6.1.0

  Solution

  Upgrade to version 5.4.6,6.1.1

  Contact

  The JSST at the Joomla! Security Centre.

  Reported By:  Jesper den Boer

• [20260519] - Framework - Inadequate content filtering within the checkAttribute filter code

  • Project: Joomla!
  • SubProject: Framewok
  • Impact: Moderate
  • Severity: Moderate
  • Probability: Moderate
  • Versions: 3.0.0-5.4.5,6.0.0-6.1.0
  • Exploit type: XSS
  • Reported Date: 2026-04-21
  • Fixed Date: 2026-05-26
  • CVE Number: CVE-2026-48903

  Description

  Inadequate content filtering within the checkAttribute methods leads to XSS vulnerabilities in various components.

  Affected Installs

  Joomla! CMS versions 3.0.0-5.4.5,6.0.0-6.1.0

  Solution

  Upgrade to version 5.4.6,6.1.1

  Contact

  The JSST at the Joomla! Security Centre.

  Reported By:  JSST

• [20260518] - Core - Transport encryption downgrade for password and username reset links

  • Project: Joomla!
  • SubProject: CMS
  • Impact: Low
  • Severity: Low
  • Probability: Low
  • Versions: 3.9.0-5.4.5,6.0.0-6.1.0
  • Exploit type: Mixed Content
  • Reported Date: 2026-04-20
  • Fixed Date: 2026-05-26
  • CVE Number: CVE-2026-48902

  Description

  The password and username reset features created plain http links for https connections if the "Force SSL" flag wasn't explicitly set.

  Affected Installs

  Joomla! CMS versions 3.9.0-5.4.5,6.0.0-6.1.0

  Solution

  Upgrade to version 5.4.6,6.1.1

  Contact

  The JSST at the Joomla! Security Centre.

  Reported By:  ZeroXJacks, Github

• [20260517] - Core - Incorrect Cache Key Construction for InputFilter objects

  • Project: Joomla!
  • SubProject: CMS
  • Impact: Low
  • Severity: Low
  • Probability: Low
  • Versions: 4.0.0-5.4.5,6.0.0-6.1.0
  • Exploit type: Incorrect Cache Key Construction
  • Reported Date: 2025-11-14
  • Fixed Date: 2026-05-26
  • CVE Number: CVE-2026-48901

  Description

  The InputFilter::getInstance() method omitted a security sensitive parameter from the instance cache key.

  Affected Installs

  Joomla! CMS versions 4.0.0-5.4.5,6.0.0-6.1.0

  Solution

  Upgrade to version 5.4.6,6.1.1

  Contact

  The JSST at the Joomla! Security Centre.

  Reported By:  ZeroXJacks, Github

• [20260516] - Core - Incorrect Access Control in com_scheduler

  • Project: Joomla!
  • SubProject: CMS
  • Impact: Moderate
  • Severity: Low
  • Probability: Low
  • Versions: 4.1.0-5.4.5,6.0.0-6.1.0
  • Exploit type: Incorrect Access Control
  • Reported Date: 2026-04-29
  • Fixed Date: 2026-05-26
  • CVE Number: CVE-2026-48900

  Description

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

  Affected Installs

  Joomla! CMS versions 4.1.0-5.4.5,6.0.0-6.1.0

  Solution

  Upgrade to version 5.4.6,6.1.1

  Contact

  The JSST at the Joomla! Security Centre.

  Reported By:  Federico Brasili, Linkedin