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YesWiki before 4.6.7 Unauthenticated Open Mail Relay via Contact Mail Handler

Priority HIGH 70CWE-306Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
None · Low · Low
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-306.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00435 38th percentileScored 2026-11-07
Fix Fixed yeswiki (YesWiki): 4.6.7

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
YesWikiyeswikibefore 4.6.74.6.7Patch availableCNA
  • yeswiki VendorYesWiki Affected before 4.6.7 Fixed in 4.6.7 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:yeswiki:yeswiki:*:*:*:*:*:*:*:*——YesWiki
  • cpe:2.3:a:yeswiki:yeswiki:*:*:*:*:*:*:*:* Versions — — ·YesWiki

Remediation

  • Fix · CNA yeswiki (YesWiki) Fixed in 4.6.7

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    yeswiki 4.6.7

    34 records Highest priority Priority HIGH 24 HIGH, 7 MEDIUM, 3 LOW

    Other records, highest priority first

    • TI-2026-66114 YesWiki before 4.6.7 Missing Authorization via Attachment Download HandlerPriority HIGH 77
    • TI-2026-66106 YesWiki before 4.6.7 SSRF via Bazar abonnements sync actor parameterPriority HIGH 77
    • TI-2026-66104 YesWiki before 4.6.7 SQL Injection via nuagetag tags parameterPriority HIGH 77

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-104446
  2. 2026-10-03 Alias added: GHSA-c595-8pv9-m3vm

References

  • TI-2026-37893 YesWiki has Unsafe eval() in Formula Calculator - Remote Code Execution (RCE) & Denial of Service (DoS) CVSS 3.1CRITICAL 9.8
  • TI-2026-34305 YesWiki: Unauthenticated SQL Injection CVSS 3.1CRITICAL 9.8
  • TI-2025-29089 YesWiki Vulnerable to Unauthenticated Site Backup Creation and Download CVSS 3.1CRITICAL 10.0
  • TI-2024-34399 Use of a Broken or Risky Cryptographic Algorithm in YesWiki CVSS 3.1CRITICAL 9.9
  • TI-2026-37882 YesWiki: Unauthenticated arbitrary page deletion via `{{erasespamedcomments}}` action CVSS 3.1CRITICAL 9.1
  • TI-2026-80227 SQL injection in YesWiki Bazar entry creation via date_maj_fiche CVSS 4.0HIGH 8.8
See all 85 →

Sources