Vercel Eve 0.78.0 closes a privilege escalation in approved tool calls

Verdict: Vercel Eve stays conditional. The fix in eve@0.78.0 is the right call, but it shipped as a breaking change in a framework that is still in beta. If your Eve agents use human approvals and you run a build older than 0.78.0, upgrade now and re-test every approval flow.

What happened

Vercel's release notes for eve@0.78.0 (October 13, 2026) describe a breaking change that closes a privilege escalation in approved calls:

• Old behavior: when another person approved a call, it ran with the approver's identity and credentials. A requester could get a tool to act with access they do not have.
• New behavior: approved calls now always run as the requester. The notes say the execution identity rule from PR #4368 was reversed.
• Policy change: tools that check approver requirements should now read response.principal in their approval.response policy.

We saw no CVE and no GitHub security advisory on the pages we read, so "privilege escalation" is Vercel's own wording, not a scored severity rating.

Why it matters

Approval is where you put a human in front of a risky tool call. On builds before 0.78.0, that safeguard could widen access instead of gating it: the person asking borrowed the approver's credentials. That is the opposite of what an approval step is for.

The framework around the fix also moves fast. As of October 30, 2026, the releases page lists eve@0.90.0 (October 29, 2026) as the latest release, twelve minor versions past 0.78.0 in about two weeks. The repository README still says Eve is in beta under the Vercel beta terms and that the framework, APIs, documentation and behavior may change before general availability. That pace is why our verdict stays conditional.

What changes for you

• On a build before 0.78.0 with human approvals: upgrade. Tools that relied on running as the approver will now run as the requester, so check that requesters hold the credentials those tools need.
• If a tool enforces who may approve: move that check to response.principal in the approval.response policy.
• Re-test approval flows end to end after the upgrade, since the identity a call runs under has changed.
• Not using approvals: no action from this change, but pin versions given the release pace.

We have not run Eve ourselves, so this reading comes from the release notes, not a reproduction.