CVE-2026-71464

LaunchConfigurationBaseSerializer.scm_branch has no validate_scm_branch() leading-dash check, unlike Project/JobTemplate/JobLaunch serializers. Schedule and WFJT Node accept --upload-pack=/bin/id as scm_branch. Currently blocked at runtime by jobs.py:1502 ValueError check (defense-in-depth), but the API validation gap means sole reliance on a task-layer guard. Refactoring that guard away would promote this to RCE.