TI-2026-38663 Aliases CVE-2026-53607 GHSA-34pj-2622-jvxq

@apostrophecms/file pretty-URL Vulnerable to Unauthenticated SSRF via Host header

MEDIUM 51CWE-918Published 2026-06-12 · Updated 2026-06-15

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: High
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

ApostropheCMS is an open-source Node.js content management system. In versions up to and including 4.30.0, when `prettyUrls: true` is enabled on `@apostrophecms/file` (a documented SEO feature for serving uploaded files at clean URLs), the public pretty-URL handler builds the upstream URL using the raw `Host` HTTP request header. That URL is then `fetch`'ed and the response body + headers are streamed straight back to the requester. Because `Host` is fully attacker-controlled, an unauthenticated remote attacker can pivot the apostrophe process to issue outbound HTTP requests against any host it can reach on the private network. The path component is constrained to `/uploads/attachments/<cuid>-<slug>.<ext>` (built from a local-DB lookup), which keeps the impact narrow: cross-instance data exfiltration is neutralized by cuid uniqueness, but blind-SSRF residuals remain (network-topology mapping via response-code / timing differences and verbose proxy/WAF 404 body disclosure). As of time of publication, no known patched versions exist.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00274 19th percentileScored 2026-11-07

Fix Fixed apostrophe (npm): 4.31.0

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	up to 4.30.0	—	No fix listed	CNA
—	apostrophe (npm)	before 4.31.0	4.31.0	Patch available	GHSA-34pj-2622-jvxq

apostrophe Vendorapostrophecms Affected up to 4.30.0 Fixed in — No fix listed CNA
apostrophe (npm) Vendor— Affected before 4.31.0 Fixed in 4.31.0 Patch available GHSA-34pj-2622-jvxq

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

Fix · GHSA-34pj-2622-jvxq apostrophe (npm) Fixed in 4.31.0 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-53607
2026-10-03 Alias added: GHSA-34pj-2622-jvxq

References

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2026-53607

Other 4

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

See all 65 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences