Use After Free Affecting ruby-json package, versions *


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.43% (35th percentile)

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  • Snyk IDSNYK-DEBIAN11-RUBYJSON-18590628
  • published8 Aug 2026
  • disclosed7 Aug 2026

Introduced: 7 Aug 2026

CVE-2026-71847  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

There is no fixed version for Debian:11 ruby-json.

NVD Description

Note: Versions mentioned in the description apply only to the upstream ruby-json package and not the ruby-json package as distributed by Debian. See How to fix? for Debian:11 relevant fixed versions and status.

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 Base Scores

version 3.1