CVE-2026-53609: CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') in apostrophecms apostrophe
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.
AI Analysis
Technical Summary
CVE-2026-53609 is a prototype pollution vulnerability in ApostropheCMS (apostrophe) affecting versions prior to 4.30.1. The vulnerability arises because apos.util.set() traverses dot-notation paths without sanitizing the __proto__ property, allowing an authenticated editor to modify Object.prototype arbitrarily using the $pullAll patch operator. A gadget in publicApiCheck() confirms this can be exploited to bypass authorization on all piece-type REST API endpoints for all subsequent unauthenticated requests within the same Node.js process. This results in a critical security risk with high impact on confidentiality, integrity, and availability. As of the publication date, no official fix or patch is available.
Potential Impact
An authenticated editor can exploit this vulnerability to perform prototype pollution, leading to arbitrary modification of Object.prototype. This causes an authorization bypass on all piece-type REST API endpoints for all unauthenticated requests during the lifetime of the Node.js process. The impact includes high confidentiality loss, partial integrity compromise, and partial availability disruption, making this a critical security issue.
Mitigation Recommendations
No official patch or fix is currently available for this vulnerability. Users should restrict editor privileges to trusted individuals and consider additional access controls or temporary workarounds until a vendor-provided fix is released. Monitor the vendor's advisory channels for updates regarding remediation.
CVE-2026-53609: CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') in apostrophecms apostrophe
Description
ApostropheCMS is an open-source Node.js content management system. In versions up to and including 4.30.0, `apos.util.set()` traverses dot-notation paths without sanitizing `__proto__`, allowing an authenticated editor to write arbitrary values to `Object.prototype` via the `$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.
CVSS v3.1
Score 9.1critical
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-53609 is a prototype pollution vulnerability in ApostropheCMS (apostrophe) affecting versions prior to 4.30.1. The vulnerability arises because apos.util.set() traverses dot-notation paths without sanitizing the __proto__ property, allowing an authenticated editor to modify Object.prototype arbitrarily using the $pullAll patch operator. A gadget in publicApiCheck() confirms this can be exploited to bypass authorization on all piece-type REST API endpoints for all subsequent unauthenticated requests within the same Node.js process. This results in a critical security risk with high impact on confidentiality, integrity, and availability. As of the publication date, no official fix or patch is available.
Potential Impact
An authenticated editor can exploit this vulnerability to perform prototype pollution, leading to arbitrary modification of Object.prototype. This causes an authorization bypass on all piece-type REST API endpoints for all unauthenticated requests during the lifetime of the Node.js process. The impact includes high confidentiality loss, partial integrity compromise, and partial availability disruption, making this a critical security issue.
Mitigation Recommendations
No official patch or fix is currently available for this vulnerability. Users should restrict editor privileges to trusted individuals and consider additional access controls or temporary workarounds until a vendor-provided fix is released. Monitor the vendor's advisory channels for updates regarding remediation.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-09T19:39:52.404Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a2c7c93e617e2d834c6c826
Added to database: 06/12/2026, 21:39:31 UTC
Last enriched: 06/19/2026, 22:20:07 UTC
Last updated: 07/31/2026, 19:22:59 UTC
Views: 182
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