Unauthenticated object injection via unsafe session deserialization
Published Sep 9, 2026 · Updated Sep 9, 2026
PHP object injection in MaxSite CMS 0.78 through 109.6 allows remote attackers to alter application state via a forged session cookie. Session.php passes decoded ci_session data to unserialize() without disabling class instantiation, so embedded objects invoke loaded magic methods. Exploitation requires forging the cookie with the default key; code execution additionally requires a usable gadget, while injection alone can corrupt application state.
Summary
What happened
PHP object injection in MaxSite CMS 0.78 through 109.6 allows remote attackers to alter application state via a forged session cookie. Session.php passes decoded ci_session data to unserialize() without disabling class instantiation, so embedded objects invoke loaded magic methods. Exploitation requires forging the cookie with the default key; code execution additionally requires a usable gadget, while injection alone can corrupt application state.
The record
- CVE
- CVE-2026-87930
- Published
- Sep 9, 2026
- Updated
- Sep 9, 2026
- Vendor
- MaxSite
- Product
- MaxSite CMS
- Classifications
- CWE-502, CAPEC-586, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 9, 2026CVE publishedPublication date reported by the CVE source.
- Sep 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0.78 <=109.6
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- MaxSite CMS unsafe unserialize object-injection proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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