CVE-2026-55455

critical

Appsmith is a platform to build admin panels, internal tools, and dashboards.

Vendor / product: Appsmith — appsmith

Appsmith is a platform to build admin panels, internal tools, and dashboards. Prior to 2.1, the outbound HTTP host filter applied by WebClientUtils (used by the REST API and GraphQL datasource plugins) validates hosts against an exact-match string denylist. The comprehensive address-class check (loopback, any-local, link-local, fc00::/7) exists only on a separate code path used by SMTP, not by the HTTP plugin path. As a result, an authenticated user can craft outbound requests that reach loopback-bound services inside the container. This vulnerability is fixed in 2.1.

CVSS

9.1

9.1 (CVSS v3.1)

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Severity source: NVD CVSS v3.1 (nvd@nist.gov)

Timeline (UTC)

Published: 2026-06-24 22:16

Modified: 2026-10-25 23:10

NVD status: Analyzed

Last synced 2 days ago

Verified against the source API 2026-10-27 07:07 UTC

Exploitation

Not listed in CISA KEV (as of last catalog sync)

Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

appsmith / appsmith <2.1

Weakness classification (CWE)

CWE-918

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

No vendor advisory or patch reference tagged by NVD. Check the references below.

References

https://github.com/appsmithorg/appsmith/security/advisories/GHSA-m23h-pvf3-2m7p security-advisories@github.com
https://github.com/appsmithorg/appsmith/security/advisories/GHSA-m23h-pvf3-2m7p 134c704f-9b21-4f2e-91b3-4a467353bcc0

Data sources

NVD CVE API 2.0 — fetched 2026-10-27 07:07 UTC · record ↗

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