Script Security Plugin 1189.vbab_7c8fd5fde and earlier stores whole-script approvals as the SHA-1 hash of the approved script. SHA-1 no longer meets the security standards for producing a cryptographically secure message digest.
Script Security Plugin 1190.v65867aa47126 uses SHA-512 for new whole-script approvals. Previously approved scripts will have their SHA-1 based whole-script approval replaced with a corresponding SHA-512 whole-script approval when the script is next used.
Whole-script approval only stores the SHA-1 or SHA-512 hash, so it is not possible to migrate all previously approved scripts automatically on startup.
Administrators concerned about SHA-1 collision attacks on the whole-script approval feature are able to revoke all previous (SHA-1) script approvals on the In-Process Script Approval page.