CVE-2026-71847

Ruby JSON is a JSON implementation for Ruby. From 2.20.0 until 2.21.2, Ruby's JSON native C extension clears the consumed JSON::ResumableParser input buffer but leaves state.start, state.cursor, and state.end pointing into released storage. When partial_value reconstructs an incomplete object containing duplicate keys, the duplicate-key warning path calls cursor_position, which dereferences those stale pointers. This results in a heap-use-after-free and can terminate the Ruby process. An attacker who can supply JSON stream data to an application using JSON::ResumableParser may cause process termination when the application calls partial_value on incomplete attacker-controlled input containing duplicate object keys. This issue has been fixed in version 2.21.2.

CVSS

No CVSS.

References

Link	Resource
https://github.com/ruby/json/security/advisories/GHSA-9hj4-r449-hfvc
https://github.com/ruby/json/security/advisories/GHSA-9hj4-r449-hfvc

Configurations

No configuration.

History

23 Oct 2026, 20:10

Type	Values Removed	Values Added
Summary		(es) Ruby JSON es una implementación de JSON para Ruby. Desde la versión 2.20.0 hasta la 2.21.2, la extensión C nativa de JSON de Ruby borra el búfer de entrada consumido de JSON::ResumableParser pero deja state.start, state.cursor y state.end apuntando a almacenamiento liberado. Cuando partial_value reconstruye un objeto incompleto que contiene claves duplicadas, la ruta de advertencia de clave duplicada llama a cursor_position, que desreferencia esos punteros obsoletos. Esto resulta en un uso después de liberación en el montón y puede terminar el proceso de Ruby. Un atacante que puede suministrar datos de flujo JSON a una aplicación que usa JSON::ResumableParser puede causar la terminación del proceso cuando la aplicación llama a partial_value en una entrada incompleta controlada por el atacante que contiene claves de objeto duplicadas. Este problema ha sido corregido en la versión 2.21.2.

Information

Published : 2026-08-07 19:18

Updated : 2026-10-24 15:10

NVD link : CVE-2026-71847

Mitre link : CVE-2026-71847

CVE.ORG link : CVE-2026-71847

JSON object : View

Products Affected

No product.

CWE

CWE-416

Use After Free

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