CVE-2026-2433

RSS Aggregator – RSS Import, News Feeds, Feed to Post, and Autoblogging <= 5.0.11 - Unauthenticated DOM-Based Reflected Cross-Site Scripting via postMessage

2026-03-06 19:00
Osvaldo Noe Gonzalez Del Rio (Os)

Strategic Overview

Status
Patched in 5.0.12
Affected Plugin
WP RSS Aggregator – RSS Import, Feed to Post, Autoblogging, AI Content
Affected Version
<= 5.0.11
CVSS
6.1Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2026-2433
View all WP RSS Aggregator – RSS Import, Feed to Post, Autoblogging, AI Content vulnerabilities

At a glance

CVE-2026-2433 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the WP RSS Aggregator WordPress plugin, affecting versions <= 5.0.11. It carries a CVSS score of 6.1 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 5.0.12; sites on affected versions should update now. Disclosed March 2026, reported by Osvaldo Noe Gonzalez Del Rio (Os).

Vulnerability Overview

The RSS Aggregator – RSS Import, News Feeds, Feed to Post, and Autoblogging plugin for WordPress is vulnerable to DOM-Based Cross-Site Scripting via postMessage in all versions up to, and including, 5.0.11. This is due to the plugin's admin-shell.js registering a global message event listener without origin validation (missing event.origin check) and directly passing user-controlled URLs to window.open() without URL scheme validation. This makes it possible for unauthenticated attackers to execute arbitrary JavaScript in the context of an authenticated administrator's session by tricking them into visiting a malicious website that sends crafted postMessage payloads to the plugin's admin page.

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.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

WP RSS Aggregator <= 5.0.11 carries this weakness at open(), and reaching it takes no account at all. 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 WP RSS Aggregator the fix is 5.0.12: builds <= 5.0.11 are affected, anything from 5.0.12 onward is not.

Remediation

Update to version 5.0.12, or a newer patched version

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: WP RSS Aggregator 5.0.12 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-2433https://www.wordfence.com/threat-intel/vulnerabilities/id/311960e7-c4b4-4638-980f-1e08ffa621bahttps://nvd.nist.gov/vuln/detail/CVE-2026-2433

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C