CVE-2026-9769: Emilstenstrom Justhtml

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

justhtml through 1.9.1 (fixed in 1.10.0) is vulnerable to uncontrolled recursion leading to denial of service. During JustHTML() construction, TreeBuilder.finish() unconditionally calls _populate_selectedcontent(), which recursively traverses the DOM tree via _find_elements()/_find_element() without a depth bound. An attacker who can supply HTML for parsing can provide deeply nested elements (e.g., ~1000 nested <div> tags, roughly 11 KB) to exceed CPython's default recursion limit and trigger an unhandled RecursionError, which may abort parsing, fail requests, or terminate a worker/process depending on the host application's exception handling.

Affected products

• Emilstenstrom Justhtml: before 1.10.0 (fixed in 1.10.0)

Published 2026-08-23. Last modified 2026-08-26.