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CVE-2026-105857: Payloadcms: Improper Control of Generation of Code

CVE-2026-105857 is rated critical with a CVSS v3.1 base score of 10.0 and affects Payloadcms. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

Payload is a free and open source headless content management system. In @payloadcms/plugin-form-builder versions before 3.90.0 and canary versions before 4.0.0-canary.34, an attacker can craft a form submission that executes code remotely on the server. This issue is fixed in versions 3.90.0 and 4.0.0-canary.34.

Severity breakdown

CVSS v3.1 10.0: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Changed. Impact reaches beyond the vulnerable component to other resources.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-94: Improper Control of Generation of Code

The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.

CWE-1321: Improperly Controlled Modification of Object Prototype Attributes

The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.

Affected products

  • Payloadcms: before 3.90.0; 4.0.0 canary0; 4.0.0 canary1; 4.0.0 canary10; 4.0.0 canary11; 4.0.0 canary12; 4.0.0 canary13; 4.0.0 canary14; 4.0.0 canary15; 4.0.0 canary16; 4.0.0 canary17; 4.0.0 canary18

References