CVE-2026-21664
CVSS 6.1 MediumEPSS 0.0%
- CVSS Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- Published: 2026-01-20T21:16:07.223
HackerOne community member Huynh Pham Thanh Luc (nigh7c0r3) has reported a reflected XSS vulnerability in the afr.php delivery script of Revive Adserver. An attacker can craft a specific URL that includes an HTML payload in a parameter. If a logged in administrator visits the URL, the HTML is sent to the browser and malicious scripts would be executed.
Related CVE by CWE
No related CWE found.
Top CVE for Vendor
No vendor taxonomy on this entry.
Recently Exploited Similar Vulnerabilities
No recent KEV-listed items for this vendor/product.
How to fix CVE-2026-21664
CVE-2026-21664 is a medium severity vulnerability affecting the affected product.
Description: HackerOne community member Huynh Pham Thanh Luc (nigh7c0r3) has reported a reflected XSS vulnerability in the afr.php delivery script of Revive Adserver. An attacker can craft a specific URL that includes an HTML payload in a parameter. If a logged in administrator visits the URL, the HTML is sent to the browser and malicious scripts […]
Exploit Difficulty: MEDIUM
⏱️ Time to exploit: 1-4 hours
🛠️ Required skills: Intermediate security knowledge
💰 Public exploits: May be available
How to Fix:
- Check if you're running the affected product
- Update to the latest patched version
- If patching is not immediately possible: restrict network exposure, apply least-privilege access
- Test the fix in a staging environment first
- Review logs for signs of exploitation
- Monitor for IOCs (Indicators of Compromise)
- Enable automatic security updates
- Set up vulnerability monitoring
- Review and harden security configurations
Description: HackerOne community member Huynh Pham Thanh Luc (nigh7c0r3) has reported a reflected XSS vulnerability in the afr.php delivery script of Revive Adserver. An attacker can craft a specific URL that includes an HTML payload in a parameter. If a logged in administrator visits the URL, the HTML is sent to the browser and malicious scripts […]
Exploit Difficulty: MEDIUM
⏱️ Time to exploit: 1-4 hours
🛠️ Required skills: Intermediate security knowledge
💰 Public exploits: May be available
How to Fix:
1 Identify affected systems
- Check if you're running the affected product
2 Immediate actions
- Update to the latest patched version
- If patching is not immediately possible: restrict network exposure, apply least-privilege access
3 Verification
- Test the fix in a staging environment first
- Review logs for signs of exploitation
- Monitor for IOCs (Indicators of Compromise)
4 Long-term prevention
- Enable automatic security updates
- Set up vulnerability monitoring
- Review and harden security configurations
Exploit Difficulty Assessment
MEDIUM
Time to Exploit: 1-4 hours
Skills Required: Intermediate security knowledge
Public Exploits: May be available
Vulnerability Timeline
Jan 20, 2026
Vulnerability Published
CVE details first published to NVD database
Jan 20, 2026
Imported to Database
Added to this CVE tracking system
Detection Rules & IOCs
No specific detection rules generated for this vulnerability type.
No vendor/product data available.