Weblate is Vulnerable to Authenticated SSRF via Project Backup Import bypassing validate_repo_url

Weblate is a web based localization tool. Prior to version 5.17.1, an authenticated user with project.add permission (default on hosted Weblate SaaS and for any user holding an active billing/trial plan) can import a crafted project backup ZIP whose components/<name>.json contains an attacker-chosen repo URL pointing at a private address (e.g. http://127.0.0.1:9999/) or using a non-allow-listed scheme (e.g. file://, git://). Weblate persists the component via Component.objects.bulk_create([component])[0], which bypasses Django's full_clean() and therefore never runs the validate_repo_url validator. The URL is subsequently written verbatim into .git/config by configure_repo(pull=False). This issue has been patched in version 5.17.1.