CVE-2026-87797

Sprout Invoices – Client Invoicing & Estimates < 20.8.16 - Authenticated (Subscriber+) Insecure Direct Object Reference

2026-09-12 00:00
Usama Arshad

Strategic Overview

Status
Patched in 20.8.16
Affected Plugin
Sprout Invoices – Client Invoicing & Estimates
Affected Version
< 20.8.16
CVSS
4.3Medium
Weakness type
CWE-639 · Authorization Bypass Through User-Controlled Key
CVE
CVE-2026-87797
View all Sprout Invoices – Client Invoicing & Estimates vulnerabilities

At a glance

CVE-2026-87797 is a medium-severity Authorization Bypass Through User-Controlled Key vulnerability in the Sprout Invoices WordPress plugin, affecting versions < 20.8.16. It carries a CVSS score of 4.3 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Subscriber level or above. The issue is fixed in version 20.8.16; sites on affected versions should update now. Disclosed September 2026, reported by Usama Arshad.

Vulnerability Overview

The Sprout Invoices – Client Invoicing & Estimates plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to 20.8.16. This is due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with subscriber-level access and above, to perform an unauthorized action.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user.

CWE-639: Authorization Bypass Through User-Controlled Key

Reaching this weakness in Sprout Invoices < 20.8.16 takes an account at Subscriber level or above. Authorization bypass through a user-controlled key, often called insecure direct object reference, means the application looks up a record by an identifier from the request without checking that the caller owns it.

Changing a number in the request is enough to read or modify other users' records, which on commerce and membership sites means customer data. For Sprout Invoices the fix is 20.8.16: builds < 20.8.16 are affected, anything from 20.8.16 onward is not.

Remediation

Update to version 20.8.16, or a newer patched version

How does WordSec protect against this?

Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: Sprout Invoices 20.8.16 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-87797https://www.wordfence.com/threat-intel/vulnerabilities/id/4d0a1a39-6421-4af1-9636-33604abd4861https://nvd.nist.gov/vuln/detail/CVE-2026-87797

Related records

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