Medium severity · published Jul 20, 2026
CVE-2026-12900
Spectra Gutenberg Blocks <= 2.19.28 - Authenticated (Contributor+) Stored Cross-Site Scripting via uagb/image Block
6.4
CVSS
0.3%
EPSS
No
On KEV
Description
The Spectra Gutenberg Blocks – Website Builder for the Block Editor plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `uagb/image` block in all versions up to, and including, 2.19.28 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 25% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SL
Spectra Legacy – Gutenberg Blocks · brainstormforce
through 2.19.28 · source: vendor
Affected product
SL
Spectra Legacy – Gutenberg Blocks
brainstormforce
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-12900
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-12900
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/ultimate-addons-for-gutenberg/tags/2.19.28/blocks-config/image/class-uagb-image.php#L59
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/ultimate-addons-for-gutenberg/tags/2.19.28/includes/blocks/image/block.php#L10
www.wordfence.com
https://www.wordfence.com/threat-intel/vulnerabilities/id/0e9dc5e3-9d72-4c04-8ba9-56428a6fdddd?source=cve
More from Spectra Legacy – Gutenberg Blocks
4.3
CVE-2026-16302
Spectra Legacy – Gutenberg Blocks <= 2.20.0 - Authenticated (Contributor+) Sensitive Information Exposure