CVE-2026-71502: Flask Jinja Missing Finalize Hook

The Flask application configures `jinja_env` without setting a `finalize` hook. If client-side template frameworks like Vue.js parse server-rendered HTML, unneutralized delimiters in rendered user data can lead to client-side template injection (XSS).

Provally CuratedPublic repositoryMediumMedium confidenceVerifiedApache-2.0Python
greprules fetch cve-2026-71502-flask-jinja-missing-finalize-hook --engine opengrep

Description

The Flask application configures `jinja_env` without setting a `finalize` hook. If client-side template frameworks like Vue.js parse server-rendered HTML, unneutralized delimiters in rendered user data can lead to client-side template injection (XSS).