# CVE-2026-54502: ruby-oj: Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem

CVE-2026-54502 is fixed in ruby-oj on 1 platform, first by DEBIAN-CVE-2026-54502, released July 3, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-54502
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0040
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 1, 2026

## Description

Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.2, Oj.dump is vulnerable to a stack-based buffer overflow when a large :indent value is provided by the developer. fill_indent in dump.h calls memset(indent_str, ' ', (size_t)opts->indent) without validating the size. When opts->indent is set to INT_MAX (2,147,483,647), the (size_t) cast preserves the large value and memset writes 2 GB into the stack-allocated out buffer (4,184 bytes), corrupting the stack and crashing the process. This issue has been fixed in version 3.17.2.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | ruby-oj Debian 12.15 (bookworm) | 3.14.2-1+deb12u1 | [DEBIAN-CVE-2026-54502](https://patchblox.com/security/data/fix/linux/debian-cve-2026-54502.md) | Jul 3, 2026 |
| Linux | ruby-oj Debian 13.5 (trixie) | 3.16.3-1+deb13u1 | [DEBIAN-CVE-2026-54502](https://patchblox.com/security/data/fix/linux/debian-cve-2026-54502.md) | Jul 3, 2026 |
| Linux | ruby-oj Debian 14 | 3.17.3-1 | [DEBIAN-CVE-2026-54502](https://patchblox.com/security/data/fix/linux/debian-cve-2026-54502.md) | Jul 3, 2026 |

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Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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