CVE-2026-66596
HighCVSS 7.1Exploitation Probability (EPSS)
Low risk4th percentile - higher than 4% of all known CVEs
Summary
Unauthenticated Cross Site Scripting (XSS) vulnerability in Newsletter plugin versions up to 9.3.3. An attacker can inject malicious script without authentication.
Risk Assessment
Risk of malicious script execution in user's browser, potentially leading to session theft, account takeover, or malware distribution.
Recommendation
Update the Newsletter plugin to the latest version that includes a fix for this vulnerability.
Other vulnerabilities in Newsletter
See all- CVE-2026-90981Medium
The Newsletter – Send awesome emails from WordPress plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'nn' parameter in all versions up to, and including, 9.3.8 due to insufficient input sanitization and output escaping. Unauthenticated attackers can inject arbitrary web scripts if they trick a user into clicking a link.
- CVE-2026-86823Medium
The Newsletter WordPress plugin before 9.3.7 does not validate the destination of the redirect performed after a public subscription action. Unauthenticated attackers can redirect users to arbitrary external sites and disclose a subscriber token that grants access to that subscriber record's front-end actions.
Original NVD description (English source)
Unauthenticated Cross Site Scripting (XSS) in Newsletter <= 9.3.3 versions.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS