Vulnerability in Yeswiki
CVE-2026-104454
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.
Vulnerability class: ReDoS (Regular Expression Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/YesWiki/yeswiki/security/advisories/GHSA-gf57-wg5m-h34q (vendor-advisory)
- www.vulncheck.com/advisories/yeswiki-before-4.6.7-redos-via-wakka-php-edit-prev… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-104454?
- CVE-2026-104454 is a medium-severity vulnerability in Yeswiki, classified under Inefficient Regular Expression Complexity. CVSS score: 5.3/10. Published 2026-10-02.
- How severe is CVE-2026-104454?
- Medium severity. CVSS v3 base score is 5.3 out of 10.