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YesWiki before 4.6.7 ReDoS via wakka.php Edit-Preview Endpoint

Priority HIGH 70CWE-1333Published · Updated

Key facts

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

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-1333.

Summary

YesWiki before 4.6.7 contains an algorithmic-complexity denial of service in the wakka.php formatter due to an O(n^2) markdown-link regex. Unauthenticated attackers can submit a small crafted body of bracket characters to the page-edit preview endpoint to pin PHP-FPM workers and saturate the pool.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00401 34th 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-2026-104454
  2. 2026-10-03 Alias added: GHSA-j46p-q3g4-r6r6

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