CVE-2025-49136: listmonk's Sprig template Injection vulnerability leads to reading of Environment Variable for low privilege user

The env and expandenv template functions which is enabled by default in Sprig enables capturing of env variables on the host. While this may not be a problem on single-user (super admin) installations, on multi-user installations, this allows non-super-admin users with campaign or template permissions to use the {{ env }} template expression to capture sensitive environment variables.

Upgrade to v5.0.2 to mitigate.