CVE-2026-55455: CWE-918: Server-Side Request Forgery (SSRF) in appsmithorg appsmith
A Server-Side Request Forgery (SSRF) vulnerability exists in appsmithorg's appsmith platform versions prior to 2.1. The issue arises because the HTTP host filter used by the REST API and GraphQL datasource plugins relies on an exact-match denylist rather than a comprehensive address-class check, allowing authenticated users to send outbound requests to loopback-bound services inside the container. This vulnerability is fixed in version 2.1.
AI Analysis
Technical Summary
CVE-2026-55455 is a Server-Side Request Forgery (SSRF) vulnerability in appsmithorg's appsmith platform before version 2.1. The outbound HTTP host filter applied by WebClientUtils for REST API and GraphQL datasource plugins validates hosts against an exact-match denylist, lacking the comprehensive address-class checks (such as loopback, any-local, link-local, fc00::/7) that are only applied in a separate SMTP code path. Consequently, an authenticated user can craft outbound HTTP requests that reach internal loopback services within the container, potentially bypassing intended network restrictions. The vulnerability is resolved in appsmith version 2.1.
Potential Impact
An authenticated user can exploit this SSRF vulnerability to send HTTP requests to internal loopback services within the container hosting appsmith. This could allow access to internal services not intended to be exposed externally, potentially leading to information disclosure or further internal attacks. The CVSS 4.0 base score is 5.3, indicating a medium severity impact with network attack vector, low attack complexity, and no user interaction required.
Mitigation Recommendations
This vulnerability is fixed in appsmith version 2.1. Users should upgrade to version 2.1 or later to remediate this issue. No official patch or temporary fix is indicated beyond upgrading. Since this is not a cloud service, remediation depends on user action to update the software.
CVE-2026-55455: CWE-918: Server-Side Request Forgery (SSRF) in appsmithorg appsmith
Description
A Server-Side Request Forgery (SSRF) vulnerability exists in appsmithorg's appsmith platform versions prior to 2.1. The issue arises because the HTTP host filter used by the REST API and GraphQL datasource plugins relies on an exact-match denylist rather than a comprehensive address-class check, allowing authenticated users to send outbound requests to loopback-bound services inside the container. This vulnerability is fixed in version 2.1.
CVSS v4.0
Score 5.3medium
Affected software
pkg:github/appsmithorg/appsmithRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-55455 is a Server-Side Request Forgery (SSRF) vulnerability in appsmithorg's appsmith platform before version 2.1. The outbound HTTP host filter applied by WebClientUtils for REST API and GraphQL datasource plugins validates hosts against an exact-match denylist, lacking the comprehensive address-class checks (such as loopback, any-local, link-local, fc00::/7) that are only applied in a separate SMTP code path. Consequently, an authenticated user can craft outbound HTTP requests that reach internal loopback services within the container, potentially bypassing intended network restrictions. The vulnerability is resolved in appsmith version 2.1.
Potential Impact
An authenticated user can exploit this SSRF vulnerability to send HTTP requests to internal loopback services within the container hosting appsmith. This could allow access to internal services not intended to be exposed externally, potentially leading to information disclosure or further internal attacks. The CVSS 4.0 base score is 5.3, indicating a medium severity impact with network attack vector, low attack complexity, and no user interaction required.
Mitigation Recommendations
This vulnerability is fixed in appsmith version 2.1. Users should upgrade to version 2.1 or later to remediate this issue. No official patch or temporary fix is indicated beyond upgrading. Since this is not a cloud service, remediation depends on user action to update the software.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-16T22:10:37.607Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a3c501e4853345fc1e45c5a
Added to database: 06/24/2026, 21:46:06 UTC
Last enriched: 06/24/2026, 22:01:53 UTC
Last updated: 06/24/2026, 23:51:19 UTC
Views: 7
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