CVE-2026-49979: Appsmith

Low severity, CVSS 2.7. EPSS: 0.4% chance of exploitation in the next 30 days.

Appsmith is a platform to build admin panels, internal tools, and dashboards. Prior to 1.99, the POST /api/v1/admin/send-test-email endpoint accepts attacker-controlled smtpHost and smtpPort values and establishes a raw JavaMail TCP connection without any IP validation. This completely bypasses WebClientUtils.IP_CHECK_FILTER, which only applies to Spring WebClient HTTP requests. Additionally, the raw MailException.getMessage() is returned verbatim in the API error response, enabling error-based internal port scanning and service banner enumeration. This vulnerability is fixed in 1.99.

Affected products

• Appsmith Appsmith: before 1.99 (fixed in 1.99)

Published 2026-06-24. Last modified 2026-06-29.