What’s Vulnerable › Vulnerabilities

CVE-2026-77759: IDOR and missing authorization in the Prospero Flow CRM transaction API allow cross-tenant reading of financial records

• Severity: high (CVSS 8.7 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-21 · updated 2026-10-15
• Weakness: CWE-639

Description

Authorization Bypass Through User-Controlled Key in the transaction API in Roskus Prospero Flow CRM 5.0.0 through 5.3.5 allows an authenticated user to read the transactions of other companies on the same instance via an incremented identifier in GET /api/transaction/{id}, which is resolved without company scoping and without any permission check.

Affected products

• Roskus Prospero Flow CRM: from 5.0.0 before 5.3.6 — fixed in 5.3.6

How to fix

Upgrade to a fixed version: Roskus Prospero Flow CRM 5.3.6. Check the vendor advisory for mitigations.

References

• https://github.com/Roskus/prospero-flow-crm/commit/980c35ac00e419591a8adc2d1dbcc120ea62e273
• https://github.com/Roskus/prospero-flow-crm/releases/tag/v5.5.3
• https://secur0.com/en/cna/cve-list/cve-2026-77759-idor-missing-authz-prospero-transaction-api

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