Master Blocks 1.4.1 - 1.4.1.4 - Unauthenticated Stored XSS via White Label Settings
Priority MEDIUM 41CWE-79Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-79.
Summary
The Master Blocks WordPress plugin before 1.5.0 does not have authorisation on one of its REST routes, allowing unauthenticated users to update its settings, including a value that is output unescaped in the admin area, leading to Stored XSS that executes in the session of any administrator visiting a wp-admin page.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00505 43rd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by the CNA
Fix Fixed Master Blocks (Unknown): 1.5.0
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Unknown | Master Blocks | 1.4.1 to before 1.5.0 | 1.5.0 | Patch available | CNA |
- Master Blocks VendorUnknown Affected 1.4.1 to before 1.5.0 Fixed in 1.5.0 Patch available CNA
Remediation
- Fix · CNA Master Blocks (Unknown) Fixed in 1.5.0
Timeline
- 2026-10-02 Threatist record created from CVE-2026-88824
- 2026-10-03 Alias added: GHSA-4qrp-9fm8-gvg2
References
Sources
- CVE-2026-88824 · CVE Program
- CVE-2026-88824 · NVD
- FIRST EPSS
- GHSA-4qrp-9fm8-gvg2 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences