---
id: "CVE-2026-78191"
kind: "vulnerability"
aliases: ["CVE-2026-78191"]
title: "WebDyne: files containing .psp anywhere in name run as Perl"
severity: "high"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["package", "perl", "self-hosted", "webdyne"]
not_affected_if: ["no-file-uploads", "static-only", "webdyne-3.022-or-later"]
published_at: "2026-10-31T15:16:54+00:00"
first_seen_at: "2026-10-31T15:36:19+00:00"
updated_at: "2026-10-31T15:36:40+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-78191", "first_seen_at": "2026-10-31T15:36:19+00:00"}]
---

# WebDyne: files containing .psp anywhere in name run as Perl

WebDyne, a Perl web framework, treats any file whose name contains .psp as a Perl page, because its matching pattern has no end anchor. An attacker who can upload a file such as report.psp.pdf can get its embedded Perl code run by requesting it.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed WebDyne version with `perl -MWebDyne -e 'print $WebDyne::VERSION'` or the `WebDyne` entry in the cpanfile or Makefile.PL.
- Search your application's upload handling for accepted extensions and whether uploaded files are stored where WebDyne serves them.
- Look for WEBDYNE_PSP_EXT_RE in your WebDyne configuration or overrides.

## Fix

- WebDyne versions from `2.031` before `3.022`: move to `3.022` or later.

## Timeline

- 2026-10-31T15:36:19+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-78191

## From the sources

WebDyne versions from 2.031 before 3.022 for Perl execute files with .psp anywhere in the name as Perl pages.

WebDyne decides whether to run a requested file as a page by matching its name against WEBDYNE_PSP_EXT_RE, which has no end anchor.

An application that accepts uploads by checking only the final extension lets a remote attacker upload a file such as report.psp.pdf and run its embedded Perl by requesting it.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_