CVE-2026-78189

Critical

Description

WebDyne versions from 3.007 before 3.022 for Perl execute .psp files outside the document root via path traversal in the PSGI API route fallback. When a request matches no file, the PSGI handler retries it as an API route through api_filename. That keeps .. segments in the request path and only checks that the joined path starts with the document root, which a request for /../private passes. A remote attacker can run the embedded Perl in any .psp file the server can read, such as one uploaded to a directory outside the document root.

SeverityCritical
CVSS9.8
Exploit probability—
ProductWebdyne
PublishedOct 31, 2026
First seenNov 4, 2026

How to fix

Update
  • WebDyne3.022 or later

Affected products

ProductAffected versionsFixed in
WebDyne3.007 ≤ v < 3.0223.022

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