Skip to content

Near-miss · Oct 22, 2026 · Agent payment rail

x402 TypeScript Solana facilitator accepted a token approval that moved no funds as a valid payment

Amount
No loss reported
local test only; no live transaction
Affected
x402 Foundation (@x402/svm facilitator)
Chains
Solana
Status
Confirmed by the affected party or a post-mortem

What happened

V12 said the TypeScript x402 facilitator code for Solana checked the token program but not the instruction type, so an ApproveChecked instruction that moves no tokens passed as a TransferChecked payment, The Hacker News reported. V12 called it 'a complete payment bypass': a merchant could deliver a paid resource while receiving nothing, and the facilitator paid the transaction fee each time. The Hacker News found every @x402/svm release from 2.0.0 to 2.22.0 lacked the check; 2.23.0 added it, and the Python and Go SDKs already checked.

Why it happened

  • Logic bug

    A bug in the bot's or agent's own logic, including code an AI wrote.

    Ask of your own agent: Which of your agent's dollars can't you explain?

Free checks for this pattern, in your browser:

Sources

  1. Critical x402 SDK Flaw Could Let Malicious APIs Drain AI Agents' Token BalancesThe Hacker News · news · Oct 23, 2026 · I checked the page: it names this incident Nov 8, 2026
  2. x402 Payment SDK Flaws: The Missing Advisory TrailCloud Security Alliance · research · Oct 26, 2026 · I checked the page: it names this incident Nov 8, 2026

Added Nov 8, 2026, last updated Nov 8, 2026. I wrote this from the sources above; nothing here goes beyond what they report. Involved in this incident, or see an error? Send a correction or a reply; replies from affected parties are added to the entry, dated.

Could the same thing happen to your agent?

Send me one real agent workflow. In my free 48-hour integration review I go through it end to end against this incident's pattern (logic bug) and send you a written report: where the same path exists, what would stop it, and the tests that prove it.

Request the free 48-hour review

This is a record of public reports, not a security audit, legal, compliance or investment advice. Names appear only as the sources report them.