CVE-2026-55455Public exploitNetwork attack vector

Authenticated internal service access via exact-match host denylist

Published Jun 24, 2026 · Updated Jun 24, 2026

SSRF in Appsmith before 2.1 allows remote authenticated users to reach loopback-bound services through crafted datasource requests. WebClientUtils requestFilterFn and Netty name resolvers compare canonical hosts only with literal denylist entries instead of rejecting resolved loopback and any-local address classes. Any Appsmith role can issue arbitrary-method requests with chosen headers and bodies to container-local services, while host takeover requires a separate vulnerable internal service.

CVSS severity5.3
Medium
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SSRF in Appsmith before 2.1 allows remote authenticated users to reach loopback-bound services through crafted datasource requests. WebClientUtils requestFilterFn and Netty name resolvers compare canonical hosts only with literal denylist entries instead of rejecting resolved loopback and any-local address classes. Any Appsmith role can issue arbitrary-method requests with chosen headers and bodies to container-local services, while host takeover requires a separate vulnerable internal service.

The record

CVE
CVE-2026-55455
Published
Jun 24, 2026
Updated
Jun 24, 2026
Vendor
Appsmith
Product
Appsmith
Classifications
CWE-918, 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

5.3GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
9.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

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-918Server-Side Request Forgery (SSRF)
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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