CVE-2026-113603: @x402/extensions 2.3.1 through 2.28.0; +2 more affected products

Affected technology

@x402/extensions · 2.3.1 through 2.28.0
x402-foundation

x402 · 2.11.0 through 2.25.0
x402-foundation

github.com/x402-foundation/x402/go/v2 · 2.16.0 through 2.28.0
x402-foundation

Description’s affected range: through 2.28.0, x402 PyPI 2.11.0 through 2.25.0, and Go module 2.16.0 through 2.28.0

Component: Not specified by the source

Attack conditions (Vendor/CNA, CVSS 4.0): Network (remote) · No privileges required · No user interaction required

What an attacker can do

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. Vendor/CNA’s CVSS 4.0 assessment (base score 6.9/10) rates confidentiality and integrity impact as low; availability impact as none.