CVE-2026-39562

Client Invoicing by Sprout Invoices <= 20.8.10 - Missing Authorization

2026-03-19 00:00

Strategic Overview

Status: Patched in 20.8.11
Affected Plugin: Sprout Invoices – Client Invoicing & Estimates
Affected Version: <= 20.8.10
CVSS: 5.3Medium
Weakness type: CWE-862 · Missing Authorization
CVE: CVE-2026-39562

View all Sprout Invoices – Client Invoicing & Estimates vulnerabilities

At a glance

CVE-2026-39562 is a medium-severity Missing Authorization vulnerability in the Sprout Invoices WordPress plugin, affecting versions <= 20.8.10. It carries a CVSS score of 5.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 20.8.11; sites on affected versions should update now. Disclosed March 2026, reported by Bao - BlueRock.

Vulnerability Overview

The Client Invoicing by Sprout Invoices plugin for WordPress is vulnerable to unauthorized access due to a missing capability check on a function in versions up to, and including, 20.8.10. This makes it possible for unauthenticated attackers 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 privileges on the target site, and no interaction from a victim user.

CWE-862: Missing Authorization

Reaching this weakness in Sprout Invoices <= 20.8.10 takes a caller who can reach the endpoint. A missing authorization check means a function is reachable by anyone who can reach the endpoint, because the code never asks whether the caller is allowed to perform the action.

Any user who can reach the endpoint gets to run an action reserved for higher-privileged roles, from reading protected data to changing settings or content. For Sprout Invoices the fix is 20.8.11: builds <= 20.8.10 are affected, anything from 20.8.11 onward is not.

Remediation

Update to version 20.8.11, 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 20.8.11 closes this, and updating the plugin is the step that ends it.

Login Security
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-39562 https://www.wordfence.com/threat-intel/vulnerabilities/id/735b20ff-a708-4e1c-b96e-bcdec72aad95 https://nvd.nist.gov/vuln/detail/CVE-2026-39562

Related records

Same weakness class

Other vulnerabilities in Sprout Invoices – Client Invoicing & Estimates

CVSS Vector

5.3

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
ConfidentialityNone
IntegrityLow
AvailabilityNone

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