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CVE-2026-113603

x402 @x402/extensions 2.3.1 through 2.28.0 SIWX Payment Bypass via PaymentPayload.resource PUBLISHED

Description (CNA)

The x402 SIWX server extension in @x402/extensions 2.3.1 through 2.28.0, x402 PyPI 2.11.0 through 2.25.0, and Go module 2.16.0 through 2.28.0 contains an authorization bypass vulnerability that allows paying clients to unlock unpaid routes by supplying a mismatched PaymentPayload.resource URL. Attackers can pay for the cheapest SIWX-protected route while setting resource.url to an expensive route, then repeatedly access it using only a SIGN-IN-WITH-X header without further payment.

Affected (CNA)

Vendor / productVersions
x402-foundation / @x402/extensionsaffected 2.3.1 through 2.28.0
x402-foundation / x402affected 2.11.0 through 2.25.0
x402-foundation / github.com/x402-foundation/x402/go/v2affected 2.16.0 through 2.28.0

CWE

CWE-639

References

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.