CVE-2026-104000: CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in croixhaug Simply Schedule Appointments
Description
The Simply Schedule Appointments plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'status' parameter in all versions up to, and including, 1.6.12.35 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. The malicious payload is stored unconditionally because debug logging is enabled by default, and the debug-log viewer is accessible to anyone holding the site-wide Support PIN (an HMAC-MD5 of AUTH_SALT displayed in wp-admin), meaning the injected script will execute against the administrator's session during ordinary support or troubleshooting workflows.
CVSS v3.1
Score 7.2high
Affected software
croixhaug
Simply Schedule Appointments
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-104000 describes a stored Cross-Site Scripting vulnerability in the Simply Schedule Appointments plugin for WordPress, affecting all versions up to and including 1.6.12.35. The vulnerability is due to improper neutralization of input in the 'status' parameter, which is not properly sanitized or escaped. Because debug logging is enabled by default and the debug-log viewer is accessible with the Support PIN (derived from AUTH_SALT), attackers can inject scripts that execute in the context of administrators accessing the debug logs, potentially compromising their sessions.
Potential Impact
An unauthenticated attacker can inject arbitrary web scripts that are stored and executed in administrator sessions during normal support or troubleshooting activities. This can lead to partial compromise of confidentiality and integrity (CVSS impact: low confidentiality and integrity impact, no availability impact). The vulnerability affects site administrators who access the debug-log viewer with the Support PIN, potentially allowing session hijacking or other malicious actions.
Mitigation Recommendations
No official patch or fix is currently documented. Users should verify with the vendor for updates. Until a fix is available, it is recommended to disable debug logging if possible and restrict access to the Support PIN and debug-log viewer to trusted personnel only. Monitor vendor advisories for official remediation.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Wordfence
- Date Reserved
- 2026-10-01T16:17:38.328Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ad1bacb2cdf04f656bb876a
Added to database: 10/16/2026, 05:48:59 UTC
Last enriched: 10/16/2026, 06:04:39 UTC
Last updated: 10/16/2026, 19:03:29 UTC
Views: 12
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