CVE-2026-54696 LOW

CVE-2026-54696: Ruby JSON: JSON generator heap buffer overflow when streaming to an IO

Vendor Ruby
Product json
Weakness CWE-122
Published June 30, 2026
Last update July 1, 2026
View on NVD All CVEs

CVSS base score

3.7/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

What the vulnerability does

01Description

Ruby JSON is a JSON implementation for Ruby. Versions 2.9.0 through 2.19.8 are vulnerable to heap buffer overflow when the JSON generator is provided with an oversized streamed object. When streaming to an IO JSON.dump(obj, io) and JSON::State#generate(obj, io) can write past the internal JSON generator buffer when a streamed object contains an attacker-controlled string near 16 KB. Exploitation would result in a reliable process crash/denial of service. This issue has been fixed in version 2.19.9.

Key dates

02Disclosure timeline

June 30, 2026 CVE published
July 1, 2026 Record updated