Server-side request forgery in ApostropheCMS AI helper image fetch
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-918 and the CVSS impact.
Summary
The @apostrophecms/ai-helper npm package from 1.0.0-beta.10 before 1.0.0-beta.13 and the apostrophe package from 4.25.0 before 4.33.0 are affected. The image acceptance step resolves a fixed uploads path against an origin taken from the request Host header, which is server-side request forgery (CWE-918). An authenticated editor with image-generation capability can make the server send bounded requests to an attacker-chosen host, port and HTTP origin on deployments that use local relative storage without a trusted global base URL.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| apostrophecms | apostrophe | 4.25.0 to before 4.33.0 | 4.33.0 | Patch available | CNA |
| apostrophecms | ai-helper | 1.0.0-beta.10 to before 1.0.0-beta.13 | 1.0.0-beta.13 | Patch available | CNA |
| — | @apostrophecms/ai-helper (npm) | 1.0.0-beta.10 to before 1.0.0-beta.13 | 1.0.0-beta.13 | Patch available | GHSA-527g-ff96-x6wj |
- apostrophe Vendorapostrophecms Affected 4.25.0 to before 4.33.0 Fixed in 4.33.0 Patch available CNA
- ai-helper Vendorapostrophecms Affected 1.0.0-beta.10 to before 1.0.0-beta.13 Fixed in 1.0.0-beta.13 Patch available CNA
- @apostrophecms/ai-helper (npm) Vendor— Affected 1.0.0-beta.10 to before 1.0.0-beta.13 Fixed in 1.0.0-beta.13 Patch available GHSA-527g-ff96-x6wj
CPE names Threatist (inferred) · 1
Inferred from how NVD named this product before; not given by a source.
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:apostrophecms:apostrophecms:*:*:*:*:*:*:*:* | — | — | apostrophecms |
- cpe:2.3:a:apostrophecms:apostrophecms:*:*:*:*:*:*:*:* Versions — — ·apostrophecms
Remediation
Upgrade @apostrophecms/ai-helper to 1.0.0-beta.13, which fixes the issue. The sources list no fixed version for apostrophe.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- Fix · CNA apostrophe (apostrophecms) Fixed in 4.33.0
- Fix · CNA ai-helper (@apostrophecms) Fixed in 1.0.0-beta.13
- Fix · GHSA-527g-ff96-x6wj @apostrophecms/ai-helper (npm) Fixed in 1.0.0-beta.13 Advisory →
Timeline
- 2026-10-20 Threatist record created from CVE-2026-113671
- 2026-10-20 CISA SSVC decision points changed
- 2026-10-20 Priority changed: LOW → MEDIUM
- 2026-10-21 Alias added: GHSA-527g-ff96-x6wj
- 2026-10-21 Fix available: npm/@apostrophecms/[email protected] · GHSA-527g-ff96-x6wj
- 2026-10-21 CVSS score added · GHSA-527g-ff96-x6wj
- 2026-10-21 Weakness changed · GHSA-527g-ff96-x6wj
- 2026-10-21 5 new references · GHSA-527g-ff96-x6wj
References
Other 5
- 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/[email protected]
- https://github.com/apostrophecms/apostrophe
More apostrophecms vulnerabilities
- TI-2026-25223 ApostropheCMS has Arbitrary File Write (Zip Slip / Path Traversal) in Import-Export Gzip Extraction CVSS 3.1CRITICAL 10.0
- TI-2026-32848 Apostrophe has default XSS via `xmp` raw-text passthrough in `sanitize-html` CVSS 3.1CRITICAL 9.3
- TI-2026-38664 @apostrophecms/seo Vulnerable to Stored XSS via Unsanitized Google Analytics / GTM ID Injected into Script Tag CVSS 3.1HIGH 8.7
- TI-2026-27673 ApostropheCMS: Stored XSS in SEO Fields Leads to Authenticated API Data Exposure in ApostropheCMS CVSS 3.1HIGH 8.7
- TI-2026-76992 Unauthenticated resource exhaustion via ApostropheCMS import routes CVSS 3.1HIGH 7.5
- TI-2026-76974 ApostropheCMS leaves rejected CSV uploads in temporary directory CVSS 3.1HIGH 7.5
Sources
- CVE-2026-113671 · CVE Program
- CVE-2026-113671 · NVD
- FIRST EPSS
- GHSA-527g-ff96-x6wj · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences