GHSA-73p9-6hrp-8qhr: Pip/aiir vulnerability

Summary Several of AIIR's verification and policy paths could return a success/"verified" result without actually enforcing the control they represent — they could fail open rather than fail closed. For a tool whose purpose is trustworthy verification, a consumer relying on these gates may have treated unverified or non-conforming input as verified.

Found during an internal adversarial hardening review of AIIR (not a third-party audit). All paths are fixed in 1.7.0.

Affected paths - A requiresigning policy gate could be satisfied by a forgeable/empty field, so an unsigned or forged-bundle receipt could pass a "signing required" check without a valid signature. - A CI verification path could report success regardless of the underlying verification result. - A release-verification gate could advertise policy limits it did not actually enforce. - A signature-verification path could be silently skipped for certain input categories, exiting success without verifying.

Impact A consumer relying on these gates (e.g. requiresigning, release/policy verification, or the CI check) to block unsigned, forged, or non-conforming receipts could have received a false "verified"/"pass". Exploitation requires reliance on the affected gate; it does not forge valid signatures, nor does it compromise content-addressing or correctly-signed receipts.

Patches Fixed in 1.7.0. Every affected path now fails closed, each with a regression test. Upgrade to aiir >= 1.7.0.

Workarounds None for earlier versions other than upgrading. Full cryptographic Sigstore verification (pip install aiir[sign], --verify-signature with --signer-identity/--signer-issuer) provides defense in depth.

Scope note This advisory covers code present in released versions (< 1.7.0). Separately, an unreleased agent-receipt feature had pre-release forgery findings fixed before it shipped — those were never in a released version and are out of scope.