TI-2026-59993 Aliases CVE-2026-87928 GHSA-283m-m2f4-x73v

MaxSite CMS 0.94 through 109.6 HTML Upload XSS via admin_page

LOW 23CWE-434Published 2026-09-09 · Updated 2026-09-24

Key facts

Attack vector: Network
Privileges required: Low
User interaction: Passive
Attack complexity: Low
Attack requirements: None
Impact type: Code execution
Confidentiality · integrity · availability: None · None · None
Fix status: No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-434.

Summary

MaxSite CMS versions 0.94 through 109.6 contain a cross-site scripting vulnerability in the admin_page upload handler that allows any logged-in user to upload HTML files. Attackers can upload HTML containing malicious scripts to the uploads/_pages/ directory, which executes in visitors' browsers when the file is accessed, enabling persistent stored cross-site scripting attacks.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00298 22nd percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by the CNA

Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

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
MaxSite	MaxSite CMS	0.94 – 109.6	—	No fix listed	CNA

MaxSite CMS VendorMaxSite Affected 0.94 – 109.6 Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2026-87928
2026-10-03 Alias added: GHSA-283m-m2f4-x73v

References

Exploit 1

https://github.com/EviL0rd/maxsite-cve2/blob/main/2026.09.08-maxsite-cms-arbitrary-file-write-stored-xss.md

Other 2

TI-2026-59994 MaxSite CMS through 109.6 Authentication Bypass via Hardcoded Encryption Key CVSS 4.0CRITICAL 9.3
TI-2026-59992 MaxSite CMS through 109.6 Local File Inclusion via ajax dispatcher CVSS 4.0HIGH 8.8
TI-2026-59995 MaxSite CMS through 109.6 PHP Object Injection via ci_session CVSS 4.0CRITICAL 9.2
TI-2026-02931 MaxSite CMS MarkItUp Preview AJAX Endpoint preview-ajax.php eval code injection CVSS 4.0MEDIUM 6.9
TI-2025-11324 MaxSite CMS save-file-ajax.php unrestricted upload CVSS 4.0MEDIUM 5.3
TI-2026-06140 MaxSite CMS ushki Plugin cross site scripting CVSS 4.0MEDIUM 4.8

See all 18 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences