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

CVE record · `CVE-2026-78191`

- **Identifiers:** `CVE-2026-78191`
- **State:** Confirmed
- **Severity:** No CVSS score
- **Critical:** No
- **CNA:** CPANSec
- **Weakness (CWE):** [CWE-777](https://cwe.mitre.org/data/definitions/777.html)
- **Tags:** [CWE-777](https://agentprime.io/advisories/tag/cwe-777.md)
- **Published:** 31 Oct 2026
- **Updated:** 31 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: CPANSec) at 31 Oct 2026, 14:34 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Affected products, as the CNA wrote them

- Vendor: Not given. Product: Not given.
  - affected: `2.031 to before 3.022` (custom)
  - Other versions: unaffected
  - Package name: `WebDyne`
  - Collection: `https://cpan.org/modules`
  - purl: `pkg:cpan/WebDyne`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> WebDyne versions from 2.031 before 3.022 treat any file with ".psp" anywhere in its name as a Perl page and run it. An attacker who can upload files to an application that checks only the final extension, for example a file named report.psp.pdf, can then request that file to execute its embedded Perl code. Upgrade WebDyne to version 3.022 or later. The source does not list a workaround other than limiting uploads to files whose names are checked for the ".psp" extension at the end.

Written 5 Nov 2026.

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

No source has published a CVSS score for this record yet.

- **CISA KEV:** Not listed.
- **EPSS:** 0.0045, the 39th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:34 UTC: [Confirmed by the CVE List](https://www.cve.org/CVERecord?id=CVE-2026-78191)
- 31 Oct 2026, 14:39 UTC: First seen by agentprime
- 31 Oct 2026, 15:16 UTC: [Confirmed by NVD](https://nvd.nist.gov/vuln/detail/CVE-2026-78191)

## Sources

- [CVE List: CVE-2026-78191](https://www.cve.org/CVERecord?id=CVE-2026-78191)
- [NVD: CVE-2026-78191](https://nvd.nist.gov/vuln/detail/CVE-2026-78191)

### References from the CNA

- <https://metacpan.org/release/ASPEER/WebDyne-3.022/changes> (release-notes)

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2026-78191>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-78191/>. Everything for agents: <https://agentprime.io/llms.txt>.