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.

CVSS 4.0

6.9CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

CVSS 3.1

5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS

0.4% chance of exploitation in the next 30 days; higher than 34% of CVEs (scores of 2026-10-25)

CWE

CWE-1333

Published

2026-10-02

Modified

2026-10-02

Record from

the NVD, synced 2026-10-19

References

• https://github.com/YesWiki/yeswiki/security/advisories/GHSA-gf57-wg5m-h34q
• https://www.vulncheck.com/advisories/yeswiki-before-4.6.7-redos-via-wakka-php-edit-preview-endpoint
• https://github.com/YesWiki/yeswiki/security/advisories/GHSA-gf57-wg5m-h34q

Check your stackJSON