CVE-2026-5418
Published: 02 April 2026
Summary
CVE-2026-5418 is a medium-severity SSRF (CWE-918) vulnerability. Its CVSS base score is 6.9 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 19.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 AC-4 (Information Flow Enforcement) and SI-10 (Information Input Validation).
Deeper analysis
CVE-2026-5418 is a server-side request forgery (SSRF) vulnerability affecting Appsmith, an open-source low-code platform developed by appsmithorg, in versions up to 1.97. The issue resides in the computeDisallowedHosts function within the file app/server/appsmith-interfaces/src/main/java/com/appsmith/util/WebClientUtils.java, part of the Dashboard component. This flaw, classified under CWE-918, has a CVSS v3.1 base score of 7.3 (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L), indicating high severity due to its network accessibility and lack of prerequisites.
Remote attackers can exploit this vulnerability without authentication by manipulating the affected function to forge requests from the server. Successful exploitation enables limited impacts on confidentiality, integrity, and availability, such as unauthorized internal network access or probing of restricted resources. A public exploit is available, increasing the risk of widespread abuse.
Mitigation involves upgrading to Appsmith version 1.99, where the vendor has addressed the issue. The security advisory GHSA-9m89-5jw7-q5cr on GitHub provides detailed patch information, and the vendor was notified early, responding professionally with a rapid fix. Additional details are available via VulDB entries and the Appsmith repository.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-18518
Vulnerability details
A vulnerability was identified in appsmithorg appsmith up to 1.97. Impacted is the function computeDisallowedHosts of the file app/server/appsmith-interfaces/src/main/java/com/appsmith/util/WebClientUtils.java of the component Dashboard. Such manipulation leads to server-side request forgery. The attack may be launched remotely. The exploit is publicly…
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available and might be used. Upgrading to version 1.99 is recommended to address this issue. The affected component should be upgraded. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
SSRF in public-facing app enables initial access via T1190; ability to forge server requests for internal probing directly facilitates T1046 Network Service Discovery.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Requires timely identification, reporting, and patching of the SSRF flaw in Appsmith's computeDisallowedHosts function by upgrading to version 1.99.
Mandates validation of inputs to the WebClientUtils component to block malicious host manipulations enabling server-side request forgery.
Enforces information flow policies to restrict server-initiated requests to only authorized destinations, mitigating unauthorized internal network access via SSRF.