CVE-2026-49979

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.

CVSS v3.1 Score

2.7

LOW

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N

EPSS — Exploit Prediction

0.0022

Probability of exploitation

0.12%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-209 CWE-209

CWE-918 Server-Side Request Forgery (SSRF)

Affected Products

Vendor	Product	Versions
appsmith	appsmith	< 1.99

References

Exploits

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

Frequently Asked Questions

What is CVE-2026-49979? +

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. It has a CVSS v3.1 base score of 2.7 (LOW).

How severe is CVE-2026-49979? +

CVE-2026-49979 has a CVSS v3.1 score of 2.7 out of 10, rated LOW. This is a low-severity vulnerability with limited impact. The EPSS score is 0.0022, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-49979? +

CVE-2026-49979 affects products from appsmith, specifically: appsmith. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-49979? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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