# CVE-2026-113671: ApostropheCMS: Host header controls server-side image fetch origin in @apostrophecms/ai-helper, enabling authenticated SSRF


- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 20 Oct 2026
- **Updated:** 20 Oct 2026
- **Also known as:** GHSA-527g-ff96-x6wj

## What is CVE-2026-113671?

CVE-2026-113671 is a medium-severity vulnerability in @apostrophecms ai-helper, published on 20 Oct 2026. 

### Official description

ApostropheCMS is an open-source Node.js content management system. From 1.0.0-beta.10 until 1.0.0-beta.13 of the AI helper, an editor with image-generation capability can create a base64-generated image record without a stored provider URL and invoke image acceptance on a deployment using local relative storage with no trusted global base URL. The server resolves the fixed uploads path against a request-controlled Host-derived origin, enabling bounded server-side requests to an attacker-selected host, port, and HTTP origin, but not arbitrary-path retrieval or the stored-provider and absolute-storage configurations. This issue is fixed in AI helper 1.0.0-beta.13.

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

## Which versions are affected by CVE-2026-113671?

2 open source packages ship an affected version, including @apostrophecms/ai-helper.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@apostrophecms/ai-helper` | npm | From 1.0.0-beta.10 | 1.0.0-beta.13 |
| `@apostrophecms/ai-helper` | npm | From 1.0.0-beta.10 | 1.0.0-beta.13 |

## How do I fix CVE-2026-113671?

Upgrade @apostrophecms/ai-helper to 1.0.0-beta.13 or later.

## Is CVE-2026-113671 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-113671 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-113671 and fix it if it is affected.

What it is: CVE-2026-113671 is a medium-severity vulnerability in @apostrophecms ai-helper, published on 20 Oct 2026. 
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-113671 exists.

Affected packages and fixed versions:
- @apostrophecms/ai-helper (npm): affected from 1.0.0-beta.10; fixed in 1.0.0-beta.13
- @apostrophecms/ai-helper (npm): affected from 1.0.0-beta.10; fixed in 1.0.0-beta.13

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-2026-113671/ (Markdown: https://insights.sbomify.com/CVE-2026-113671/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-113671
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-113671
- OSV: https://osv.dev/vulnerability/CVE-2026-113671

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-113671/
Summaries are generated and may contain mistakes; the official description above is the record.