High 8.1Published Sep 9, 2026

CVE-2026-87930MaxSite CMS through 109.6 PHP Object Injection via ci_session

Updated under an hour ago (Oct 27, 2026, 10:30 AM ET)

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No exploitation reported and no EPSS estimate yet.

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Every CVE for MaxSite CMS

Exploited in the last 30 days

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.

CVSS: 8.1 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-502
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: VulnCheck
NVD analysis: Deferred
Record last updated: Sep 24, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

MaxSite MaxSite CMS maxsite:cms (from the name)	from 0.78 through 109.6	CNA record

References

References

https://github.com/maxsite/cms	product
https://github.com/EviL0rd/maxsite-cve6/blob/main/2026.09.08-maxsite-cms-unsafe-unserialize-object-injection.md	exploit, technical-description
https://github.com/maxsite/cms/blob/2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c/system/libraries/Session.php#L670-L680	technical-description
https://github.com/maxsite/cms/blob/2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c/system/libraries/Session.php#L740-L742	technical-description
https://github.com/EviL0rd/maxsite-cve4/blob/main/2026.09.08-maxsite-cms-hardcoded-session-key-auth-bypass.md	technical-description
https://github.com/maxsite/cms/blob/2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c/application/config/config.php#L230-L254	technical-description
https://www.vulncheck.com/advisories/maxsite-cms-through-109.6-php-object-injection-via-ci-session	third-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.