AIKIDO-2026-845986

TL;DR

When uv resolves a locked source distribution from uv.lock, it can read package metadata and invoke the build backend for the cached source archive before checking that archive against the hash recorded in the lockfile. A source archive that has been swapped or corrupted at its recorded location can therefore have its build backend executed before the mismatch is caught, exposing the machine running uv sync or uv lock to code from an unverified artifact. Hash verification under --verify-hashes and --require-hashes also failed to apply supplied hashes to === exact-version requirements and to requirements resolved to a local version, letting content pass the hash check for those version forms. The fix verifies locked source archives before reading metadata or building and corrects the hash-matching strategy for exact pins and local versions.