Medium severity · published Jul 29, 2026
CVE-2026-66490
Joomla Extension - balbooa.com - Stored cross-site scripting via a comment avatar in Gridbox < 2.20.2
6.1
CVSS
0.3%
EPSS
No
On KEV
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 18% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
GE
Gridbox extension for Joomla · balbooa.com
1.0.0-2.20.1 · source: vendor
GR
Gridbox · Balbooa
before 2.20.2 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-66490
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-66490
Third Party Advisory
https://mysites.guru/blog/gridbox-23-critical-vulnerabilities/
Product
https://www.balbooa.com/gridbox
More from Gridbox extension for Joomla
9.8
CVE-2026-65888
Joomla Extension - balbooa.com - Account takeover vulnerability in Gridbox < 2.20.2
9.8
CVE-2026-65887
Joomla Extension - balbooa.com - Unauthenticated arbitrary password reset in Gridbox < 2.20.2
9.8
CVE-2026-65890
Joomla Extension - balbooa.com - Unauthenticated SQL injection in Gridbox < 2.20.2
9.8
CVE-2026-65884
Joomla Extension - balbooa.com - Privilege Escalation in Gridbox < 2.20.2
9.4
CVE-2026-61425
Joomla Extension - balbooa.com - Authentication bypass in Gridbox < 1.6.0