CVE-2021-23354: Adaltas Printf

High severity, CVSS 7.5. EPSS: 2.2% chance of exploitation in the next 30 days.

The package printf before 0.6.1 are vulnerable to Regular Expression Denial of Service (ReDoS) via the regex string /\%(?:\(([\w_.]+)\)|([1-9]\d*)\$)?([0 +\-\]*)(\*|\d+)?(\.)?(\*|\d+)?[hlL]?([\%bscdeEfFgGioOuxX])/g in lib/printf.js. The vulnerable regular expression has cubic worst-case time complexity.

Affected products

• Adaltas Printf: before 0.6.1 (fixed in 0.6.1)

Published 2021-03-12. Last modified 2026-06-17.