CVE-2026-113603 (GCVE-0-2026-113603)

Vulnerability from cvelistv5 – Published: 2026-10-20 15:40 – Updated: 2026-10-20 15:40
VLAI
Title
x402 @x402/extensions 2.3.1 through 2.28.0 SIWX Payment Bypass via PaymentPayload.resource
Summary
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.
Severity
6.9 (Medium)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
CWE
  • CWE-639 - Authorization Bypass Through User-Controlled Key
Assigner
VulnCheck CNA under the mitre root
CNA scorecard B 84/100 over 6614 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
x402-foundation @x402/extensions Affected: 2.3.1 , ≤ 2.28.0 (semver)
guessed Create a notification for this product.
x402-foundation x402 Affected: 2.11.0 , ≤ 2.25.0 (semver)
guessed Create a notification for this product.
x402-foundation github.com/x402-foundation/x402/go/v2 Affected: 2.16.0 , ≤ 2.28.0 (semver)
guessed Create a notification for this product.
Date Public
2026-10-17 12:38
Credits
CBF, Lza
Show details on NVD website
To clipboard 

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}



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