Vulnerability · Published Jun 24, 2026 · Assigned by GitHub_M

CVE-2026-49979Appsmith: SSRF via `POST /api/v1/admin/send-test-email` — JavaMail Bypasses WebClient IP Filter

Medium 5.1

In plain English

A medium-severity server-side request forgery in appsmith from appsmithorg. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities).

Severity (CVSS 4.0)5.1Medium

Exploit odds (30 days)0.4%top 69.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 (as reported)

Vendor	Product	Versions
appsmithorg	appsmith	< 1.99

Weakness: CWE-209, CWE-918 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N

References

https://github.com/appsmithorg/appsmith/security/advisories/GHSA-vvxf-f8q9-86gh x_refsource_CONFIRM