TI-2026-38665 Aliases CVE-2026-53609 GHSA-6h5j-32cf-4253

Prototype pollution in apostrophecms apostrophe

HIGH 72CWE-1321Published 2026-06-12 · Updated 2026-06-15

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: High · Low · Low
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

ApostropheCMS is an open-source Node.js content management system. In versions up to and including 4.30.0, `apos.util.set()` traverses dot-notation paths without sanitizing `__proto__`, allowing an authenticated editor to write arbitrary values to `Object.prototype` via the `$pullAll` patch operator. A confirmed gadget in `publicApiCheck()` causes this to bypass authorization on all piece-type REST API endpoints for every subsequent unauthenticated request, for the lifetime of the Node.js process. As of time of publication, no known patched versions are available.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00346 28th 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-6h5j-32cf-4253

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-6h5j-32cf-4253

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-6h5j-32cf-4253 apostrophe (npm) Fixed in 4.31.0 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-53609
2026-10-03 Alias added: GHSA-6h5j-32cf-4253

References

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2026-53609

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