Analysis · curated 22 Aug 2026
Denial of Wallet
First reported pipelab.org
Coverage timeline
Single-source analysis — first reported, latest, and curated coincide.
Why it matters
Denial of wallet turns metered AI-agent access into runaway spend, a distinct financial-impact threat that defenders relying on per-session rate caps may not adequately contain.
PipeLab's explainer defines "denial of wallet" as a cost-abuse attack against metered AI-agent systems, where a hijacked, prompt-injected, or looping agent repeatedly calls paid surfaces (model tokens, tool calls, MCP servers, SaaS APIs) until the bill or quota is exhausted. The page argues that per-session budget caps fail because agents can reset the session lifecycle to mint fresh allowances, and pitches Pipelock v3.3, which keys budgets to a derived identity subject rather than an MCP session id.