CVE-2026-34415: Xerte Online Toolkits File Upload RCE via elfinder Connector

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-22 · updated 2026-10-26
Weakness: CWE-184

Description

Xerte Online Toolkits versions 3.15 and earlier contain an incomplete input validation vulnerability in the elFinder connector endpoint that fails to block PHP-executable extensions .php4 due to an incorrect regex pattern. Unauthenticated attackers can exploit this flaw combined with authentication bypass and path traversal vulnerabilities to upload malicious PHP code, rename it with a .php4 extension, and execute arbitrary operating system commands on the server.

Affected products

thexerteproject xerteonlinetoolkits: through 3.15.0

References

https://github.com/bootstrapbool/xerteonlinetoolkits-rce
https://github.com/thexerteproject/xerteonlinetoolkits/commit/02661be88cc369325ea01b508086bde7fbfec805
https://github.com/thexerteproject/xerteonlinetoolkits/commit/17e4f945fe6a3400fa88c01eda18c1075ee4a212
https://github.com/thexerteproject/xerteonlinetoolkits/commit/507d55c5e91bf9310b5b1c7fad8aebfef902ad23
https://github.com/thexerteproject/xerteonlinetoolkits/issues/1527
https://www.vulncheck.com/advisories/xerte-online-toolkits-file-upload-rce-via-elfinder-connector
https://xerte.org.uk/index.php/en/downloads-1/category/3-xerte-online-toolkits
https://xerte.org.uk/xertetoolkits_3.15_ChangeLog.html

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