# CVE-2026-55455: Appsmith: SSRF in REST API / GraphQL datasource plugins via insufficient host denylist

> Authenticated users can bypass host restrictions to access internal loopback services via REST or GraphQL plugins.

- **Severity:** Medium 5.3 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Jun 2026
- **Updated:** 25 Jun 2026
- **Also known as:** BIT-appsmith-2026-55455, GHSA-m23h-pvf3-2m7p

## What is CVE-2026-55455?

CVE-2026-55455 is a medium-severity server-side request forgery vulnerability in appsmithorg appsmith, published on 24 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

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.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-55455?

1 open source package ship an affected version, including appsmith. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `appsmith` | Bitnami | All versions | 2.1.0 |

Products: Appsmith Appsmith.

## How do I fix CVE-2026-55455?

Upgrade appsmith to 2.1.0 or later.

## Is CVE-2026-55455 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55455 exists.

## Other vulnerabilities in appsmithorg appsmith

- [CVE-2026-55454](https://insights.sbomify.com/CVE-2026-55454/): Appsmith: Caddy admin API exposed without authentication (critical 9.9)
- [CVE-2024-55964](https://insights.sbomify.com/CVE-2024-55964/): Code injection in n/a (critical 9.8)
- [CVE-2026-22794](https://insights.sbomify.com/CVE-2026-22794/): Account Takeover Vulnerability in Appsmith (critical 9.7)
- [CVE-2026-24042](https://insights.sbomify.com/CVE-2026-24042/): Appsmith public apps can execute unpublished actions (viewMode confusion) (critical 9.4)
- [CVE-2026-30862](https://insights.sbomify.com/CVE-2026-30862/): Critical Stored XSS & Privilege Escalation in Appsmith (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55455 and fix it if it is affected.

What it is: CVE-2026-55455 is a medium-severity server-side request forgery vulnerability in appsmithorg appsmith, published on 24 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55455 exists.

Affected packages and fixed versions:
- appsmith (Bitnami): affected all versions; fixed in 2.1.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-55455/ (Markdown: https://insights.sbomify.com/CVE-2026-55455/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55455
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55455
- OSV: https://osv.dev/vulnerability/CVE-2026-55455

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55455/
Summaries are generated and may contain mistakes; the official description above is the record.