GHSA-pwgq-6779-q657: 
JavaScript vulnerability analysis and mitigation

Impact

createPincerPayMiddleware in @pincerpay/merchant versions before 0.10.2 settled payments using the payment requirements taken from the agent-supplied payment header (accepted) and never compared the amount, asset, network or payTo with the route's configured price or the merchant's wallet. The PincerPay facilitator did not check them either. A client could submit a payment for a lower amount, or to its own wallet, and still receive the paywalled resource.

Patches

• @pincerpay/merchant 0.10.2: the middleware matches the agent's accepted terms against the options the route offered (scheme, network, amount, asset, payTo; EVM addresses case-insensitive) and sends its own copy of the terms to the facilitator. Mismatches are rejected with 402 payment_requirements_mismatch.
• Hosted facilitator (deployed 2026-10-30): /v1/settle and /v1/verify reject any payTo that is not the calling merchant's registered wallet (403 pay_to_not_merchant_wallet). This also protects integrations still on older SDK versions or hand-rolled clients when they use the hosted facilitator.

Workarounds

Upgrade to @pincerpay/merchant@0.10.2 or later. Self-hosted facilitators should also update to the latest apps/facilitator.

Credit

Found during an internal assumptions review on 2026-10-29.