CVE-2026-77820: CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in stellarwp WPComplete
The WPComplete WordPress plugin (pro version) up to and including 2.9.9.0 is vulnerable to stored Cross-Site Scripting (XSS) via an 'empty' shortcode attribute. This vulnerability allows authenticated users with contributor-level access or higher to inject malicious scripts that execute when other users view the affected pages.
AI Analysis
Technical Summary
CVE-2026-77820 is a stored XSS vulnerability in the WPComplete plugin for WordPress, affecting all versions up to 2.9.9.0. The flaw arises from insufficient input sanitization and output escaping of an 'empty' shortcode attribute. Exploitation requires the premium (pro) version of the plugin and contributor-level or higher privileges. The vulnerability enables injection of arbitrary web scripts that execute in the context of users visiting the compromised pages.
Potential Impact
An attacker with contributor-level access or above can inject malicious scripts into pages via the vulnerable shortcode attribute. These scripts execute in the browsers of users who view the infected pages, potentially leading to session hijacking, privilege escalation, or other client-side attacks. The impact is limited to confidentiality and integrity of user interactions, with no direct availability impact.
Mitigation Recommendations
No official patch or fix is currently documented. Users should monitor the vendor's advisories for updates. Until a fix is available, restrict contributor-level access to trusted users only and consider disabling or limiting use of the vulnerable shortcode attribute in the pro version of WPComplete.
CVE-2026-77820: CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in stellarwp WPComplete
Description
The WPComplete WordPress plugin (pro version) up to and including 2.9.9.0 is vulnerable to stored Cross-Site Scripting (XSS) via an 'empty' shortcode attribute. This vulnerability allows authenticated users with contributor-level access or higher to inject malicious scripts that execute when other users view the affected pages.
CVSS v3.1
Score 6.4medium
Affected software
stellarwp
WPComplete
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-77820 is a stored XSS vulnerability in the WPComplete plugin for WordPress, affecting all versions up to 2.9.9.0. The flaw arises from insufficient input sanitization and output escaping of an 'empty' shortcode attribute. Exploitation requires the premium (pro) version of the plugin and contributor-level or higher privileges. The vulnerability enables injection of arbitrary web scripts that execute in the context of users visiting the compromised pages.
Potential Impact
An attacker with contributor-level access or above can inject malicious scripts into pages via the vulnerable shortcode attribute. These scripts execute in the browsers of users who view the infected pages, potentially leading to session hijacking, privilege escalation, or other client-side attacks. The impact is limited to confidentiality and integrity of user interactions, with no direct availability impact.
Mitigation Recommendations
No official patch or fix is currently documented. Users should monitor the vendor's advisories for updates. Until a fix is available, restrict contributor-level access to trusted users only and consider disabling or limiting use of the vulnerable shortcode attribute in the pro version of WPComplete.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Wordfence
- Date Reserved
- 2026-08-21T14:34:54.494Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6aade9a455bf5e2cf5f2e3cb
Added to database: 09/19/2026, 01:47:16 UTC
Last enriched: 09/19/2026, 02:01:29 UTC
Last updated: 09/19/2026, 03:55:39 UTC
Views: 7
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