CVE-2026-54502

Oj: Stack Buffer Overflow in Oj.dump via Large Indent

MEDIUM
6.3
CVSS Score
Published: June 30, 2026 at 11:10 PM UTC
Updated: October 25, 2026 at 05:10 PM UTC
1 product affected across 1 vendorOj

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Severity
MEDIUM6.3
Exploit prediction
EPSS 0.4%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 3.17.2
Affected range stops below 3.17.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

SSVC — Action Prioritization

SSVCPoCAutomatableTotal impact

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CVSS

6.3MEDIUMGitHub_M
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-121

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