RSS Aggregator Plugin up to 5.0.11 on WordPress admin-shell.js postMessage cross site scripting

Summaryinfo

A vulnerability identified as problematic has been detected in RSS Aggregator Plugin up to 5.0.11 on WordPress. Affected by this vulnerability is the function postMessage of the file admin-shell.js. The manipulation leads to cross site scripting. This vulnerability is uniquely identified as CVE-2026-2433. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability was found in RSS Aggregator Plugin up to 5.0.11 on WordPress and classified as problematic. This issue affects the function postMessage of the file admin-shell.js. The manipulation with an unknown input leads to a cross site scripting vulnerability. Using CWE to declare the problem leads to CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. Impacted is integrity. The summary by CVE is:

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.

It is possible to read the advisory at wordfence.com. The identification of this vulnerability is CVE-2026-2433. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1059.007 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-10137). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• WordPress Plugin

Name

• RSS Aggregator Plugin

Version

• 5.0.0
• 5.0.1
• 5.0.2
• 5.0.3
• 5.0.4
• 5.0.5
• 5.0.6
• 5.0.7
• 5.0.8
• 5.0.9
• 5.0.10
• 5.0.11

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

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Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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