Crossbearing is a read-only evidence engine that runs inside your own cloud account: it holds no customer data, has no backend and no sub-processors, and cannot create, modify, or delete anything in the environments it reads. Most classes of vulnerability therefore can't apply to a hosted service we operate — there isn't one. What we do care about, and want reported, is anything that could undermine the integrity of the evidence or the read-only guarantee.

Email hello@crossbearing.dev with Security in the subject. Please do not open a public issue, pull request, or discussion for a suspected vulnerability.

Helpful to include:

• What you found and the affected repository, version, or aep/1 package.
• Steps to reproduce, or a proof of concept.
• The impact you see — especially anything that lets evidence be forged, tampered with undetected, attributed to the wrong identity, or that would let the engine perform a write against a customer environment.

We'll acknowledge your report within 3 business days, keep you updated as we investigate, and credit you when a fix ships if you'd like the credit. We're an early-stage team, so timelines are honest rather than contractual — but integrity reports go to the front of the queue.

If you need to encrypt your report, say so in a first plaintext email (no sensitive details) and we'll arrange a key.

• Evidence integrity — any way to alter, reorder, drop, splice, or transplant findings in an Agent Evidence Package (aep/1) without the hash chain or detached signature catching it; any flaw in the canonicalization the offline verifier relies on; any path that makes a tampered package verify, or a valid one fail to verify.
• Attribution correctness — a way to make a record corroborate a claim it shouldn't, bind an action to the wrong identity, or make an unattributed action read as attributed (or vice-versa).
• The read-only guarantee — any code path, dependency, or IAM requirement in the engine that could perform a write against a customer environment, or exfiltrate data outside the customer's account.
• Supply chain — anything that breaks the lean-dependency property: an unexpected transitive dependency, or a way crossbearing/verify's zero- dependency claim could be violated.

• Findings that require already having privileged access to the customer's account or audit logs (the engine reads what that account already records).
• Theoretical issues without a realistic path to forged or mis-attributed evidence.
• Reports against third-party services (AWS, GitHub, etc.) themselves — please report those to the respective vendor.

You don't have to trust us to check a package we (or one of our partners) produced. crossbearing/verify is an MIT-licensed, zero-dependency tool that re-derives an Agent Evidence Package's hash chain and signature offline, without importing the engine. If a package fails to verify, that's exactly the kind of thing we want to hear about.

Thank you for helping keep the evidence trustworthy.