Unauthenticated Stripe Billing Portal Session Creation

A missing authentication vulnerability in Chaskiq through commit 46dfdd1 allows unauthenticated remote attackers to mint Stripe Billing Portal sessions for any tenant via the stripeCustomerPortal GraphQL mutation. The mutation performs no authentication or authorization checks before creating a customer portal session linked to any tenant Stripe account. An attacker can access and manage subscription data for any tenant without credentials.

Casky was already ahead

This CVE exploits attack patterns that Casky's 283matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

This vulnerability in Chaskiq represents a critical authentication bypass that exposes multi-tenant SaaS environments to unauthorized access. The stripeCustomerPortal GraphQL mutation fails to validate user credentials or tenant ownership before minting Stripe Billing Portal sessions, allowing attackers to access and manipulate subscription data, billing information, and customer records across any tenant without authentication. Organizations using Chaskiq for customer communication and billing integration are directly affected, as are their end customers whose sensitive billing and subscription data becomes accessible to unauthenticated threat actors. The high CVSS score of 8.6 reflects the severity of unrestricted access to payment infrastructure and customer financial data.

Casky's 283 mapped security skills detect the attack patterns underlying this vulnerability by analyzing both initial access and exploitation techniques. Detection focuses on TA0004 (Privilege Escalation) patterns—specifically how the mutation allows privilege elevation from unauthenticated to authenticated tenant-level access—and TA0006 (Credential Access) patterns that capture unauthorized retrieval of billing portal sessions and customer data. Practitioners using Casky would see findings highlighting abnormal GraphQL mutation requests to stripeCustomerPortal lacking proper authentication headers or session tokens, anomalous cross-tenant API calls, and patterns consistent with CWE-306 (Missing Authentication for Critical Function). Extended reasoning capabilities enable practitioners to correlate request patterns, identify reconnaissance attempts testing the mutation's authentication boundaries, and recognize exploitation attempts across multiple tenant accounts—providing visibility into both active exploitation and lateral movement within their environment.

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Casky Risk Score

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EPSS Probability

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Shodan Exposure

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GreyNoise Signal

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Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

283 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-72535.

abusing-dpapi-for-credential-access

red teaming · high

Run

abusing-shadow-credentials-for-privesc

red teaming · high

Run

Access with Stolen Session Cookie

cryptography · low

Run

MITRE ATT&CK Techniques

TA0004 TA0006

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