CVE-2026-87930

MaxSite CMS through 109.6 PHP Object Injection via ci_session

9.2 CriticalPublic exploit

MaxSite CMS through 109.6 passes the ci_session cookie to unserialize() without class restrictions, allowing unauthenticated attackers to inject PHP objects. Attackers can forge valid session cookies using the hardcoded encryption key to trigger magic methods and corrupt application state or achieve code execution if gadget classes exist.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

0.61%Up 0.3 points since Sep 10, 2026

What each source reports

CVE List Score used 9.2

MaxSite CMS through 109.6 PHP Object Injection via ci_session

Record: CVE-2026-87930
CVSS 4.0: 9.2 CriticalCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-502
Updated: 2026-11-02

EUVDEUVD-2026-75112 9.2

Record: EUVD-2026-75112
CVSS 4.0: 9.2 CriticalCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-2phq-cm26-22pm 9.2

MaxSite CMS through 109.6 passes the ci_session cookie to unserialize() without class...

Record: GHSA-2phq-cm26-22pm
CVSS 4.0: 9.2 CriticalCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-502
Updated: 2026-11-02

NVD 9.2

Record: CVE-2026-87930
CVSS 4.0: 9.2 CriticalCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-502
Updated: 2026-11-02

Affected products

maxsite cms

Public exploits

Links only. Every CVE stores no exploit code.

Public exploits
Source	Link	Date
PoC in GitHub	winrarzipsexploit/CVE-2026-87930	2026-09-17

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, PoC in GitHub

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-87930 is a critical vulnerability (CVSS 9.2) in Maxsite Cms, published September 9, 2026. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 0.61%, the 49th percentile. No source names a fixed version.