Smash Balloon feed id shortcode attribute permits Contributor stored XSS

Smash Balloon Social Post Feed through 4.9.0 does not adequately sanitize and escape the id attribute of its feed shortcode. A Contributor can store a script-capable value in post content, and the payload executes whenever a visitor views the affected feed. The public.

CVE / CNA score 6.4 CVSS 3.1 · security@wordfence.com

NVD score Pending NVD has not published its own CVSS assessment.

Component: Smash Balloon Social Post Feed – Simple Social Feeds for WordPress
Plugin slug: custom-facebook-feed
Affected: <= 4.9.0
Safe version: See mitigation notes
Published: Aug 16, 2026
Weakness: CWE-79 — Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

This CVE was published Aug 16, 2026 and is one of 5 known issues for this plugin.

What to do

Update, patch or deactivate.

This archive could not verify a fixed version from the official author release notes reviewed on 2026-10-13. Disable the affected feature or component where practical until remediation for the deployed configuration is established. restrict Contributors or disable affected shortcodes, review content, and invalidate privileged sessions if malicious output was viewed. Official author release notes: https://wordpress.org/plugins/custom-facebook-feed/.

No confirmed safe version is listed. Consider a vendor-supported patch or temporarily restricting the affected functionality while you assess the risk.

Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.

Source record

Technical description

The Smash Balloon Social Post Feed – Simple Social Feeds for WordPress plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'id' Shortcode Attribute in all versions up to, and including, 4.9.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

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

References

Primary and upstream sources

Data attribution: This product uses the NVD API but is not endorsed or certified by the NVD.

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