SA-2026-007: Vault keys were stored in the GitHub Actions cache

What it is

The workflow cached the vault clones. A clone's .sg_vault/local/ holds its key, and an Actions cache written by the default branch can be restored by a workflow on any branch.

What an attacker could do

Any agent able to push a branch could add a workflow that restored the cache and read six vault keys without touching the secrets.

How: Push a branch with a workflow that restores synthetic-vaults-* and prints .sg_vault/local.

Root cause

The cache was treated as data, but a vault clone is a credential store.

What contributed

• Nobody had looked at what sgit keeps in .sg_vault/local.

What was not in place

Knowing which files are credentials, and keeping them out of shared caches.

The fix

The cache step was removed; each run cloned fresh from the secret.

What prevents it now

Vault clones live outside the repository and are never cached (REQUIREMENTS.md).