Unauthenticated handler execution via base64 path traversal
Published Sep 9, 2026 · Updated Sep 9, 2026
Local file inclusion in MaxSite CMS 0.78 through 109.6 allows remote attackers to execute privileged handlers via crafted requests. The ajax and require-maxsite dispatchers prepend base_dir to a base64-decoded URI segment, validate the unresolved path with strpos(), and pass it to require(). No authentication or user interaction is required; traversal can invoke admin-gated PHP handlers, exposing sensitive functions and enabling high-integrity changes.
Summary
What happened
Local file inclusion in MaxSite CMS 0.78 through 109.6 allows remote attackers to execute privileged handlers via crafted requests. The ajax and require-maxsite dispatchers prepend base_dir to a base64-decoded URI segment, validate the unresolved path with strpos(), and pass it to require(). No authentication or user interaction is required; traversal can invoke admin-gated PHP handlers, exposing sensitive functions and enabling high-integrity changes.
The record
- CVE
- CVE-2026-87927
- Published
- Sep 9, 2026
- Updated
- Sep 9, 2026
- Vendor
- MaxSite
- Product
- MaxSite CMS
- Classifications
- CWE-98, 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?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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 ajax and require-maxsite path-traversal proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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