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. (CVE-2026-104454)
YesWiki versions prior to 4.6.7 have a denial of service vulnerability caused by an inefficient O(n^2) regular expression in the wakka.php markdown-link formatter. This flaw allows unauthenticated attackers to submit crafted bracket characters to the page-edit preview endpoint, which can exhaust PHP-FPM worker processes and cause service disruption.
AI Analysis
Technical Summary
The vulnerability in YesWiki before version 4.6.7 is an algorithmic-complexity denial of service (DoS) in the wakka.php formatter. It arises from a quadratic time complexity regular expression used to parse markdown links. An attacker can exploit this by sending a small, specially crafted input consisting of bracket characters to the page-edit preview endpoint without authentication. This input causes excessive CPU consumption, pinning PHP-FPM workers and saturating the worker pool, leading to denial of service.
Potential Impact
The impact is limited to denial of service through resource exhaustion of PHP-FPM workers. There is no confidentiality or integrity impact. The vulnerability can be triggered remotely by unauthenticated attackers, potentially causing service unavailability.
Mitigation Recommendations
A fix is available in YesWiki version 4.6.7. Users should upgrade to version 4.6.7 or later to remediate this vulnerability. No other mitigation guidance is provided or necessary.
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. (CVE-2026-104454)
Description
YesWiki versions prior to 4.6.7 have a denial of service vulnerability caused by an inefficient O(n^2) regular expression in the wakka.php markdown-link formatter. This flaw allows unauthenticated attackers to submit crafted bracket characters to the page-edit preview endpoint, which can exhaust PHP-FPM worker processes and cause service disruption.
CVSS v3.1
Score 5.3medium
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in YesWiki before version 4.6.7 is an algorithmic-complexity denial of service (DoS) in the wakka.php formatter. It arises from a quadratic time complexity regular expression used to parse markdown links. An attacker can exploit this by sending a small, specially crafted input consisting of bracket characters to the page-edit preview endpoint without authentication. This input causes excessive CPU consumption, pinning PHP-FPM workers and saturating the worker pool, leading to denial of service.
Potential Impact
The impact is limited to denial of service through resource exhaustion of PHP-FPM workers. There is no confidentiality or integrity impact. The vulnerability can be triggered remotely by unauthenticated attackers, potentially causing service unavailability.
Mitigation Recommendations
A fix is available in YesWiki version 4.6.7. Users should upgrade to version 4.6.7 or later to remediate this vulnerability. No other mitigation guidance is provided or necessary.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-j46p-q3g4-r6r6
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-104454"]
- Database Specific Severity
- MODERATE
- Cvss Version
- 3.1
Threat ID: 6abfee8ea43b0b3b89e55036
Added to database: 10/02/2026, 17:49:02 UTC
Last enriched: 10/02/2026, 17:58:39 UTC
Last updated: 10/02/2026, 21:26:10 UTC
Views: 2
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