CVE-2026-115303
LowCVSS 3.7Exploitation Probability (EPSS)
Low risk13th percentile - higher than 13% of all known CVEs
Summary
The Contact Form by Supsystic WordPress plugin before 1.11.1 does not strip CR/LF characters or re-validate submitted field values before concatenating them into outgoing email headers when a form maps a submitted field to its Reply-To, From, or Cc header. This allows unauthenticated users to inject arbitrary email headers, such as additional Bcc or Cc recipients, into the notification email.
Risk Assessment
An attacker could abuse the form to send messages to unintended recipients or conduct phishing and spam campaigns from a trusted site address. This may harm the organization's reputation and email security.
Recommendation
Update the plugin to version 1.11.1 or later. Additionally, review the form field-to-header mapping configuration and restrict this feature where possible.
Other vulnerabilities in Contact Form by Supsystic
See all- CVE-2026-115595Medium
The Contact Form by Supsystic plugin through version 1.10.7 contains a missing authorization vulnerability that allows exploitation of incorrectly configured access control security levels.
- CVE-2026-115591High
Insertion of Sensitive Information Into Sent Data vulnerability in Supsystic Contact Form by Supsystic contact-form-by-supsystic allows Retrieve Embedded Sensitive Data. This issue affects Contact Form by Supsystic: from n/a through 1.10.5.
- CVE-2026-83625High
The Contact Form by Supsystic plugin for WordPress is vulnerable to Stored Cross-Site Scripting via IP Address Header in all versions up to, and including, 1.10.2 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. An unauthenticated attacker can first call the 'updateNonce' action — which is accessible without authentication due to its absence from the plugin's permission list — to obtain a valid nonce, then submit a contact form with a malicious payload in a spoofed IP header such as X-Forwarded-For.
- CVE-2026-73379Medium
The Contact Form by Supsystic plugin version earlier than 1.10.0 has a bypass vulnerability that does not require authentication. This means an unauthenticated attacker can bypass security mechanisms and gain unauthorized access.
- CVE-2026-73378High
Unauthenticated Cross Site Scripting (XSS) vulnerability in Contact Form by Supsystic versions prior to 1.10.0.
Original NVD description (English source)
The Contact Form by Supsystic WordPress plugin before 1.11.1 does not strip CR/LF characters or re-validate submitted field values before concatenating them into outgoing email headers when a form is configured to map a submitted field into its Reply-To, From or Cc header, allowing unauthenticated users to inject arbitrary email headers such as additional Bcc or Cc recipients into the notification email.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS