CVE-2026-96649

Frontend Post Submission Manager Lite <= 1.3.4 - Unauthenticated Stored DOM-Based Cross-Site Scripting via post_content Parameter (data-label DOM Sink)

2026-09-29 13:55

Tarcísio Luchesi De Almeida Silva (Poystick)

Strategic Overview

Status: Patched in 1.3.5
Affected Plugin: Frontend Post Submission Manager Lite – Guest Post and Frontend Submission Forms
Affected Version: <= 1.3.4
CVSS: 7.2High
Weakness type: CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE: CVE-2026-96649

View all Frontend Post Submission Manager Lite – Guest Post and Frontend Submission Forms vulnerabilities

At a glance

CVE-2026-96649 is a high-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Frontend Post Submission Manager Lite WordPress plugin, affecting versions <= 1.3.4. It carries a CVSS score of 7.2 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 1.3.5; sites on affected versions should update now. Disclosed September 2026, reported by Tarcísio Luchesi De Almeida Silva (Poystick).

Vulnerability Overview

The Frontend Post Submission Manager Lite – Frontend Posting WordPress Plugin plugin for WordPress is vulnerable to Stored DOM-Based Cross-Site Scripting via post_content Parameter (data-label DOM Sink) in all versions up to, and including, 1.3.4 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This requires the site operator to have enabled guest post submission via the [fpsm] shortcode, which registers a publicly accessible AJAX handler gated only by a nonce emitted on every page containing the shortcode.

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

Reaching this weakness in Frontend Post Submission Manager Lite <= 1.3.4 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 Frontend Post Submission Manager Lite the fix is 1.3.5: builds <= 1.3.4 are affected, anything from 1.3.5 onward is not.

Remediation

Update to version 1.3.5, 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: Frontend Post Submission Manager Lite 1.3.5 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-2026-96649 https://www.wordfence.com/threat-intel/vulnerabilities/id/0af8ff06-68e2-4a0c-9de4-d06a6a2e86c9 https://nvd.nist.gov/vuln/detail/CVE-2026-96649

Related records

CVSS Vector

7.2

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

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeChanged
ConfidentialityLow
IntegrityLow
AvailabilityNone

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