CVE-2026-49979 Appsmith: SSRF via `POST /api/v1/admin/send-test-email` — JavaMail Bypasses WebClient IP Filter
Attackers can exploit an SSRF vulnerability in Appsmith's email testing endpoint to bypass IP filters and enumerate internal services via error messages.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-49979?
CVE-2026-49979 is a medium-severity server-side request forgery vulnerability in appsmithorg appsmith, published on 24 Jun 2026. An attacker needs administrator access to exploit it, with no action from the victim.
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.
Which versions are affected by CVE-2026-49979?
It affects 1 product.
Products include Appsmith Appsmith.
How do I fix CVE-2026-49979?
Upgrade to a fixed version.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-49979 being exploited?
There is no known exploitation of CVE-2026-49979 in the wild and no public exploit code.
Other vulnerabilities in appsmithorg appsmith
- CVE-2026-55454 Appsmith: Caddy admin API exposed without authentication
- CVE-2024-55964 Code injection in n/a
- CVE-2026-22794 Account Takeover Vulnerability in Appsmith
- CVE-2026-24042 Appsmith public apps can execute unpublished actions (viewMode confusion)
- CVE-2026-30862 Critical Stored XSS & Privilege Escalation in Appsmith