Cyber Resilience

CVE-2026-55454

Appsmith ≤ 2.1

Public PoC
Published
24 June 2026
Modified
26 June 2026
CVSS Score v3.1 9.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0039 32th percentile
Risk Priority 68 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 Default Accounts (T1078.001); ranked at the 32th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-6 (Least Privilege) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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…

more

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 Techniques

T1078.001 Default Accounts Stealth
Adversaries may obtain and abuse credentials of a default account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.
T1078 Valid Accounts Stealth
Adversaries may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.
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.
T1542.002 Component Firmware Stealth
Adversaries may modify component firmware to persist on systems.
T1556 Modify Authentication Process Defense Impairment
Adversaries may modify authentication mechanisms and processes to access user credentials or enable otherwise unwarranted access to accounts.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-34411Same product: Appsmith Appsmith
CVE-2026-24042Same product: Appsmith Appsmith
CVE-2024-51408Same product: Appsmith Appsmith
CVE-2026-50189Same product: Appsmith Appsmith
CVE-2026-55455Same product: Appsmith Appsmith
CVE-2026-7299Same product: Appsmith Appsmith
CVE-2026-49979Same product: Appsmith Appsmith
CVE-2026-30862Same product: Appsmith Appsmith
CVE-2026-22794Same product: Appsmith Appsmith
CVE-2024-55965Same product: Appsmith Appsmith

Affected Assets

appsmith
appsmith
≤ 2.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 17 hardening rules · 7 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V14.3.2
  • V6.3.2
  • V11.3.1
  • V13.2.3

Mitigating Controls (NIST 800-53 r5) AI

Access enforcement directly stops unauthorized callers from invoking dangerous API methods or functions.

Least privilege restricts which users or processes may reach dangerous methods, limiting exposure.

Baseline configuration directly requires documenting and maintaining secure initial settings instead of insecure defaults.

Configuration settings mandate the most restrictive values be applied at initialization, eliminating reliance on insecure factory defaults.

Least functionality removes or disables non-essential dangerous methods from the exposed interface altogether.

Security engineering principles include explicit requirements for secure defaults during resource initialization and design.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-05 full match
prevents

Enforcing least-privilege authorization directly prevents unrestricted dangerous API methods.

PR.PS-01 full match
prevents

Hardened baselines and configuration management directly replace insecure defaults with secure settings.

PR.PS-06 mostly match
prevents

Secure SDLC practices stop developers from exposing dangerous functions in the first place.

ID.RA-01 partial match
prevents

Vulnerability identification processes will surface exposed dangerous methods during assessment.

ID.RA-09 partial match
prevents

Pre-acquisition integrity checks can reject products known to ship with insecure defaults.

PR.IR-01 partial match
prevents

Logical access controls at the network/environment layer can limit reachability of exposed functions.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing can detect exposed dangerous functions, but does not prevent their initial introduction.

prevents

Mandating secure baseline templates and immediate replacement of vendor defaults directly stops systems from being deployed with insecure factory settings that attackers can exploit.

degrades

Restricting privileged utility programs reduces exposure of dangerous functions, but does not eliminate the underlying weakness.

prevents

Privileged access rights limit who can invoke dangerous methods, but do not address whether the method itself should exist.

prevents

Secure development life cycle requires removal or protection of dangerous APIs during design and coding.

prevents

Application security requirements can mandate that dangerous methods are not exposed in interfaces.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248823 OL 8 must not have the telnet-server package installed. prevents CWE-1188
RHEL 7 (1 rule)
  • V-204627 SNMP community strings on the Red Hat Enterprise Linux operating system must be changed from the default. prevents CWE-1188
Ubuntu 22.04 (3 rules)
  • V-260529 Ubuntu 22.04 LTS must be configured so that remote X connections are disabled, unless to fulfill documented and validated mission requirements. prevents CWE-1188, CWE-749
  • V-260559 Ubuntu 22.04 LTS must ensure only users who need access to security functions are part of sudo group. prevents CWE-749
  • V-260557 Ubuntu 22.04 LTS must be configured to use AppArmor. prevents CWE-749
Ubuntu 24.04 (2 rules)
  • V-270708 Ubuntu 24.04 LTS must be configured so that remote X connections are disabled, unless to fulfill documented and validated mission requirements. prevents CWE-1188
  • V-270748 Ubuntu 24.04 LTS must ensure only users who need access to security functions are part of sudo group. prevents CWE-749
Windows Server 2016 (1 rule)
  • V-224972 Active Directory Group Policy objects must have proper access control permissions. prevents CWE-1188
Windows Server 2019 (1 rule)
  • V-205741 Windows Server 2019 Active Directory Group Policy objects must have proper access control permissions. prevents CWE-1188

References