CVE-2026-55454Public exploitNetwork attack vector

Reverse-proxy takeover via exposed Caddy admin API

Published Jun 24, 2026 · Updated Jun 24, 2026

Exposed Caddy admin API in Appsmith before 2.1 allows remote authenticated users to take over the reverse proxy through server-side requests. Appsmith binds the unauthenticated Caddy admin listener to 0.0.0.0:2019, allowing a crafted POST /load request to replace its live configuration. Low-privileged access is sufficient through the companion SSRF; Kubernetes clusters with metrics enabled expose the listener cluster-wide, enabling traffic interception and credential disclosure.

CVSS severity9.9
Critical
EPSS probability0.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Exposed Caddy admin API in Appsmith before 2.1 allows remote authenticated users to take over the reverse proxy through server-side requests. Appsmith binds the unauthenticated Caddy admin listener to 0.0.0.0:2019, allowing a crafted POST /load request to replace its live configuration. Low-privileged access is sufficient through the companion SSRF; Kubernetes clusters with metrics enabled expose the listener cluster-wide, enabling traffic interception and credential disclosure.

The record

CVE
CVE-2026-55454
Published
Jun 24, 2026
Updated
Jun 24, 2026
Vendor
Appsmith
Product
Appsmith
Classifications
CWE-749, CWE-1188, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Appsmith · Appsmithversion=< 2.1

Published CVSS scores

9.9GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-749Exposed Dangerous Method or Function
CWE-1188Initialization of a Resource with an Insecure Default
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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