Progress Planner <= 1.9.0 - Authenticated (Editor+) Stored Cross-Site Scripting
Strategic Overview
- Status
- Patched in 1.9.1
- Affected Plugin
- Progress Planner
- Affected Version
<= 1.9.0- CVSS
- 4.4Medium
- Weakness type
- CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- CVE
CVE-2026-28116
At a glance
CVE-2026-28116 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Progress Planner WordPress plugin, affecting versions <= 1.9.0. It carries a CVSS score of 4.4 (reachable over the network). Exploitation requires an authenticated account at Editor level or above. The issue is fixed in version 1.9.1; sites on affected versions should update now. Disclosed June 2026, reported by hongdo.
Vulnerability Overview
The Progress Planner plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to, and including, 1.9.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with editor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, and no interaction from a victim user.
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Reaching this weakness in Progress Planner <= 1.9.0 takes an account at Editor level or above. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.
Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For Progress Planner the fix is 1.9.1: builds <= 1.9.0 are affected, anything from 1.9.1 onward is not.
Remediation
Update to version 1.9.1, or a newer patched version
How does WordSec protect against this?
An attacker needs Editor access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Progress Planner 1.9.1 closes this, and updating the plugin is the step that ends it.
- Firewall
- Alerts
External References
Related records
Same weakness class
Other vulnerabilities in Progress Planner
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