MaxSite CMS through 109.6 PHP Object Injection via ci_session
48Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 9.2epss 0.3%
from disclosure to weapon8 days
Published on NVDSep 9
1st PoC+8d
exploitation probability
0.3%top 73% of all CVEs
observed exploitation
nono source reports it
2 public exploit(s)
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:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Affected products
MaxSite · MaxSite CMSpublic PoCs found — 2
githubgithub.com/winrarzipsexploit/CVE-2026-87930★ 1cve_referencegithub.com/EviL0rd/maxsite-cve6/blob/main/2026.09.08-maxsite-cms-unsafe-unserialize-object-injection.mdunverified⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
References
https://github.com/EviL0rd/maxsite-cve4/blob/main/2026.09.08-maxsite-cms-hardcoded-session-key-auth-bypass.mdhttps://github.com/EviL0rd/maxsite-cve6/blob/main/2026.09.08-maxsite-cms-unsafe-unserialize-object-injection.mdhttps://github.com/maxsite/cmshttps://github.com/maxsite/cms/blob/2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c/application/config/config.php#L230-L254https://github.com/maxsite/cms/blob/2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c/system/libraries/Session.php#L670-L680https://github.com/maxsite/cms/blob/2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c/system/libraries/Session.php#L740-L742https://www.vulncheck.com/advisories/maxsite-cms-through-109.6-php-object-injection-via-ci-session