🛡️ CVE-2026-55455 — appsmith

🟡 CVSS 5.0 — Medium ✅ No Known Exploit CWE-918 OSV
5.0
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Appsmith: SSRF in REST API / GraphQL datasource plugins via insufficient host denylist

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.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability none.

Weakness class

CVE-2026-55455 is classified as CWE-918: Server-Side Request Forgery (SSRF). The server fetches a URL supplied by the caller, which can be pointed at internal systems it alone can reach.

Affected software

CVE-2026-55455 is recorded against 1 package.

  • appsmith

Timeline and source

Published on 29 June 2026 and last revised on 8 July 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

github.com (Web)
nvd.nist.gov (Web)

Details

Severity MEDIUM
CVSS Score 5.0
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CWE CWE-918
Public Exploit ✅ No
Source OSV
Published 2026-06-29
Updated 2026-08-12
Modified 2026-07-08
Fix URL N/A

Affected Packages

Software From version Fixed in
appsmith — —

Similar Threats

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