CVE-2026-103918: CWE-915: Improperly Controlled Modification of Dynamically-Determined Object Attributes in middleapi orpc
CVE-2026-103918 is a vulnerability in the orpc tool of middleapi prior to version 1.14.10. It involves improper control of dynamically-determined object attributes in the ZodSmartCoercionPlugin and experimental_ZodSmartCoercionPlugin, allowing a remote client to supply a __proto__ property that can replace the prototype of the returned request object. This can cause attacker-controlled inherited values to affect application lookups or trigger unhandled TypeErrors during validation. The issue does not modify global or unrelated objects and only affects crafted requests. The vulnerability is fixed in version 1.14.10.
AI Analysis
Technical Summary
The vulnerability CVE-2026-103918 affects the orpc tool in middleapi versions before 1.14.10. The affected plugins collect object and record properties in plain objects and resolve shape keys through the prototype chain. A remote attacker able to reach a procedure with an object or record input can supply a __proto__ property, replacing the prototype of the returned request object. This allows attacker-controlled inherited values to influence application lookups. For object schemas, keys like constructor, toString, and __proto__ may resolve inherited members as Zod schemas, causing unhandled TypeErrors before validation. The vulnerability does not affect the global Object.prototype or other unrelated objects and is limited to crafted requests without persistent process-wide impact. The issue is resolved in version 1.14.10.
Potential Impact
The vulnerability allows an attacker to supply a __proto__ property in object or record inputs to procedures, replacing the prototype of the returned request object. This can lead to attacker-controlled inherited values affecting application lookups and cause unhandled TypeErrors during validation. There is no modification of global or unrelated objects, and the impact is limited to crafted requests, with no persistent or process-wide availability impact. The CVSS score is 6.5 (medium severity), indicating limited confidentiality and integrity impact without availability impact.
Mitigation Recommendations
Upgrade to orpc version 1.14.10 or later, where this vulnerability is fixed. No other mitigation is required as the issue is resolved in this official fix.
CVE-2026-103918: CWE-915: Improperly Controlled Modification of Dynamically-Determined Object Attributes in middleapi orpc
Description
CVE-2026-103918 is a vulnerability in the orpc tool of middleapi prior to version 1.14.10. It involves improper control of dynamically-determined object attributes in the ZodSmartCoercionPlugin and experimental_ZodSmartCoercionPlugin, allowing a remote client to supply a __proto__ property that can replace the prototype of the returned request object. This can cause attacker-controlled inherited values to affect application lookups or trigger unhandled TypeErrors during validation. The issue does not modify global or unrelated objects and only affects crafted requests. The vulnerability is fixed in version 1.14.10.
CVSS v3.1
Score 6.5medium
Affected software
middleapi
orpc
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-103918 affects the orpc tool in middleapi versions before 1.14.10. The affected plugins collect object and record properties in plain objects and resolve shape keys through the prototype chain. A remote attacker able to reach a procedure with an object or record input can supply a __proto__ property, replacing the prototype of the returned request object. This allows attacker-controlled inherited values to influence application lookups. For object schemas, keys like constructor, toString, and __proto__ may resolve inherited members as Zod schemas, causing unhandled TypeErrors before validation. The vulnerability does not affect the global Object.prototype or other unrelated objects and is limited to crafted requests without persistent process-wide impact. The issue is resolved in version 1.14.10.
Potential Impact
The vulnerability allows an attacker to supply a __proto__ property in object or record inputs to procedures, replacing the prototype of the returned request object. This can lead to attacker-controlled inherited values affecting application lookups and cause unhandled TypeErrors during validation. There is no modification of global or unrelated objects, and the impact is limited to crafted requests, with no persistent or process-wide availability impact. The CVSS score is 6.5 (medium severity), indicating limited confidentiality and integrity impact without availability impact.
Mitigation Recommendations
Upgrade to orpc version 1.14.10 or later, where this vulnerability is fixed. No other mitigation is required as the issue is resolved in this official fix.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-10-01T14:20:19.153Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ac01129a43b0b3b89fe436c
Added to database: 10/02/2026, 20:16:41 UTC
Last enriched: 10/02/2026, 20:32:32 UTC
Last updated: 10/02/2026, 20:55:38 UTC
Views: 5
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