Cyber Resilience

CVE-2026-55454

CriticalPublic PoC

Published: 24 June 2026

Published
24 June 2026
Modified
26 June 2026
KEV Added
Patch
CVSS Score v3.1 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0033 24.6th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-55454 is a critical-severity Exposed Dangerous Method or Function (CWE-749) vulnerability in Appsmith Appsmith. Its CVSS base score is 9.9 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 24.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

Appsmith is a platform to build admin panels, internal tools, and dashboards. Prior to 2.1, the bundled Caddy reverse-proxy's admin API — which has no authentication by default — is bound on 0.0.0.0:2019 inside the container. While this listener is…

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not directly published to the host by docker-compose.yml, it is reachable from the Appsmith server process itself or a SSRF vulnerability. An authenticated low-privileged user can therefore drive the SSRF to issue POST /load (or any other admin-API call) against http://0.0.0.0:2019/, fully replacing the live Caddy configuration and taking over the reverse proxy. This vulnerability is fixed in 2.1.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1133 External Remote Services Persistence
Adversaries may leverage external-facing remote services to initially access and/or persist within a network.
Why these techniques?

SSRF reaches unauthenticated Caddy admin API allowing config replacement and proxy takeover, directly enabling exploitation of the exposed application and external remote services.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

Affected Assets

appsmith
appsmith
≤ 2.1

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-749 CWE-1188

Explicitly prohibiting dangerous or unnecessary functions and services prevents exposure of methods that could be directly exploited.

addresses: CWE-1188

Requires documented secure initialization practices and avoidance of insecure defaults in configuration baselines.

addresses: CWE-1188

Reviewing and updating baseline when components are installed or upgraded prevents initialization with insecure defaults.

addresses: CWE-1188

Tailoring replaces or augments insecure default initializations with system-specific values and compensating controls before deployment.

addresses: CWE-1188

Central configuration overrides or replaces insecure default initializations that would otherwise be left unchanged on each system.

addresses: CWE-1188

SCRM practices during acquisition and configuration management address insecure default initializations shipped by vendors.

addresses: CWE-1188

Scans detect resources initialized with insecure defaults that create exploitable conditions.

addresses: CWE-1188

Instruction on secure initialization of security controls prevents leaving resources with insecure defaults after installation.

References