CVE-2026-87930
MaxSite CMS through 109.6 PHP Object Injection via ci_session
CVSS Score
8.1
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-502 |
| Vendor | maxsite |
| Product | maxsite cms |
| Published | Sep 9, 2026 |
| Last Updated | Sep 9, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
MaxSite / MaxSite CMS
0.78 ≤ 109.6
References
github.com: https://github.com/maxsite/cms github.com: https://github.com/EviL0rd/maxsite-cve6/blob/main/2026.09.08-maxsite-cms-unsafe-unserialize-object-injection.md github.com: https://github.com/maxsite/cms/blob/2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c/system/libraries/Session.php#L670-L680 github.com: https://github.com/maxsite/cms/blob/2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c/system/libraries/Session.php#L740-L742 github.com: https://github.com/EviL0rd/maxsite-cve4/blob/main/2026.09.08-maxsite-cms-hardcoded-session-key-auth-bypass.md github.com: https://github.com/maxsite/cms/blob/2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c/application/config/config.php#L230-L254 vulncheck.com: https://www.vulncheck.com/advisories/maxsite-cms-through-109.6-php-object-injection-via-ci-session
Credits
🔍 EVIL0RD