Is CVE-2026-87927 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-87927 being exploited in the wild.

How severe is CVE-2026-87927?

High severity, with a CVSS score of 8.2, published 9 September 2026.

Is there a fix for CVE-2026-87927?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-87927 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-87927?

Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-87927: MaxSite CMS local file inclusion via base64 path traversal

CVE-2026-87927 · Severity: high · CVSS 8.2 · Published 2026-09-09

MaxSite CMS is a website content management system that handles requests through dispatcher files. The vulnerability allows unauthenticated attackers to include and execute arbitrary PHP files by supplying specially crafted base64-encoded path traversal sequences, bypassing validation checks that are meant to restrict file access. This can lead to unauthorized code execution and exposure of sensitive administrative functionality.

Quick answers

Is CVE-2026-87927 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-87927 being exploited in the wild.
How severe is CVE-2026-87927?: High severity, with a CVSS score of 8.2, published 9 September 2026.
Which products and versions are affected?: MaxSite CMS through 109.6.
Is there a fix for CVE-2026-87927?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-87927 attacked?: It is attacked over the network, in a web application.
Am I affected by CVE-2026-87927?: Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

This is a local file inclusion (LFI) vulnerability in the ajax and require-maxsite dispatchers (application/views/ajax.php and application/views/require-maxsite.php). The root cause is a flawed path validation check: the code constructs a file path by concatenating base_dir with a base64-decoded attacker-controlled URI segment, then uses a substring check (strpos) to validate containment. Because the attacker input is appended to base_dir, the resulting path always contains base_dir as a leading substring even when the input contains ../ sequences that escape the intended directory. An unauthenticated attacker can send a request to /ajax/<base64-encoded-path> with a path traversal payload to include arbitrary files ending in -ajax.php or -require-maxsite.php. Included files are executed as PHP, potentially allowing code execution if a writable handler file is reached. The fix requires replacing the substring check with canonical path resolution (realpath) and explicitly rejecting .. sequences or maintaining an allowlist of permitted handlers.

Affected products

MaxSite CMS through 109.6

Timeline

2026-09-09: disclosed

References

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