What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-02 · updated 2026-10-02
• Weakness: CWE-306

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.

Affected products

• yeswiki: before 4.6.7 — fixed in 4.6.7

How to fix

Upgrade to a fixed version: yeswiki 4.6.7. Check the vendor advisory for mitigations.

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
• https://github.com/YesWiki/yeswiki/security/advisories/GHSA-36fx-49jj-57rw

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