CVE-2026-4519: Python

Low severity, CVSS 3.3. EPSS: 0.4% chance of exploitation in the next 30 days.

The webbrowser.open() API would accept leading dashes in the URL which could be handled as command line options for certain web browsers. New behavior rejects leading dashes. Users are recommended to sanitize URLs prior to passing to webbrowser.open().

Affected products

• Python Python: before 3.13.13 (fixed in 3.13.13); from 3.14.0, before 3.14.4 (fixed in 3.14.4); version 3.15.0 only

Published 2026-03-20. Last modified 2026-08-13.