Copyright © 2012 Red Hat, Inc. All rights reserved. Important 2026-06-30T23:42:06 oj: Oj: Heap corruption and Denial of Service via integer overflow in JSON parsing 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CWE-787

Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.2, Oj.load is vulnerable to heap corruption when parsing a JSON string longer than 2 GB. An integer overflow in buf_append_string (buf.h:61) converts the string length to a large negative size_t, causing memcpy to copy an astronomically large amount of data out of bounds. This crashes the process and can corrupt adjacent heap memory. The issue has been fixed in version 3.17.2.

A flaw was found in Oj, an Optimized JSON (JavaScript Object Notation) parser for Ruby. This vulnerability allows a remote attacker to cause heap corruption and a denial of service (DoS) by providing a JSON string larger than 2 gigabytes (GB). An integer overflow occurs when processing the string length, leading to out-of-bounds memory access and a process crash. This issue could also potentially corrupt adjacent heap memory.

Red Hat's only product shipping the Oj Ruby gem (Compliance Backend) already includes version 3.17.3, which contains the fix for this vulnerability. No Red Hat products are affected. https://www.cve.org/CVERecord?id=CVE-2026-54903 https://nvd.nist.gov/vuln/detail/CVE-2026-54903 https://github.com/ohler55/oj/security/advisories/GHSA-475m-ph3x-64gp