Storage-layout collision risk across upgrades

Sky Lending (formerly MakerDAO)'s assessment for RD-F-142 — scored green on the v1.7.0 rubric. The evidence below is the curator's reasoning for this score.

Evidence summary #

USDS uses UUPS with OZ _disableInitializers() + standard OZ storage layout. ChainSecurity 2024 Sky smart contracts audit included upgrade path and storage layout analysis. Single USDS upgrade event (Sept 2024 initial). No storage-layout collision reported in any audit.

Sources #

URL
https://www.chainsecurity.com/security-audit/makerdao-sky-smart-contractsretrieved 2026-04-28
Etherscan
https://etherscan.io/address/0xdC035D45d973E3EC169d2276DDab16f1e407384F#eventsretrieved 2026-04-28

Methodology #

Determine whether the OZ upgrades-plugin or manual review flags a storage-layout collision risk between implementation versions.

See the full factor methodology and distribution across all protocols →

rubric_version v1.7.0 protocol sky-lending factor RD-F-142 score green collected_at 2026-04-28 00:43:18