CVE-2026-55455

Appsmith is a platform to build admin panels, internal tools, and dashboards. Prior to 2.1, the outbound HTTP host filter applied by WebClientUtils (used by the REST API and GraphQL datasource plugins) validates hosts against an exact-match string denylist. The comprehensive address-class check (loopback, any-local, link-local, fc00::/7) exists only on a separate code path used by SMTP, not by the HTTP plugin path. As a result, an authenticated user can craft outbound requests that reach loopback-bound services inside the container. This vulnerability is fixed in 2.1.

CVSS v3 9.1 CRITICAL

9.1^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/appsmithorg/appsmith/security/advisories/GHSA-m23h-pvf3-2m7p	Third Party Advisory
https://github.com/appsmithorg/appsmith/security/advisories/GHSA-m23h-pvf3-2m7p	Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:appsmith:appsmith:*:*:*:*:*:*:*:*

History

26 Jun 2026, 19:50

Type	Values Removed	Values Added
First Time		Appsmith Appsmith appsmith
CPE		cpe:2.3:a:appsmith:appsmith::::::::
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 9.1
References	~~() https://github.com/appsmithorg/appsmith/security/advisories/GHSA-m23h-pvf3-2m7p -~~	() https://github.com/appsmithorg/appsmith/security/advisories/GHSA-m23h-pvf3-2m7p - Third Party Advisory

25 Jun 2026, 14:16

Type	Values Removed	Values Added
References	~~() https://github.com/appsmithorg/appsmith/security/advisories/GHSA-m23h-pvf3-2m7p -~~	() https://github.com/appsmithorg/appsmith/security/advisories/GHSA-m23h-pvf3-2m7p -

24 Jun 2026, 22:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-06-24 22:16

Updated : 2026-06-26 19:50

NVD link : CVE-2026-55455

Mitre link : CVE-2026-55455

CVE.ORG link : CVE-2026-55455

JSON object : View

Products Affected

appsmith

appsmith

CWE

CWE-918

Server-Side Request Forgery (SSRF)

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