CVE-2026-54901: CWE-416: Use After Free in ohler55 oj
Oj (Optimized JSON) is a Ruby gem for JSON parsing and object marshalling. Versions prior to 3.17.2 have a Use-After-Free vulnerability in Oj::Parser when running in usual mode. This occurs because array_class and hash_class references are not marked during garbage collection, potentially leading to a dangling pointer and a segmentation fault during parsing. The issue is fixed in version 3.17.2.
AI Analysis
Technical Summary
CVE-2026-54901 is a Use-After-Free vulnerability (CWE-416) in the Oj Ruby gem versions before 3.17.2. The vulnerability arises because Oj::Parser does not mark array_class and hash_class references during garbage collection in usual mode. If garbage collection occurs after these classes are assigned but before a parse operation, the class objects may be reclaimed, leaving the parser with dangling VALUE pointers. Subsequent parse calls dereference these freed objects, causing segmentation faults. This issue has been addressed and fixed in version 3.17.2.
Potential Impact
Exploitation of this vulnerability can cause a segmentation fault in applications using vulnerable versions of the Oj gem, potentially leading to denial of service. There is no indication of code execution or data corruption beyond the crash. The CVSS 4.0 base score is 6.3 (medium severity), reflecting network attack vector, low attack complexity, no privileges required, no user interaction, and limited impact to availability.
Mitigation Recommendations
Upgrade to Oj version 3.17.2 or later, where this Use-After-Free vulnerability is fixed. No other mitigations are indicated or required.
CVE-2026-54901: CWE-416: Use After Free in ohler55 oj
Description
Oj (Optimized JSON) is a Ruby gem for JSON parsing and object marshalling. Versions prior to 3.17.2 have a Use-After-Free vulnerability in Oj::Parser when running in usual mode. This occurs because array_class and hash_class references are not marked during garbage collection, potentially leading to a dangling pointer and a segmentation fault during parsing. The issue is fixed in version 3.17.2.
CVSS v4.0
Score 6.3medium
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-54901 is a Use-After-Free vulnerability (CWE-416) in the Oj Ruby gem versions before 3.17.2. The vulnerability arises because Oj::Parser does not mark array_class and hash_class references during garbage collection in usual mode. If garbage collection occurs after these classes are assigned but before a parse operation, the class objects may be reclaimed, leaving the parser with dangling VALUE pointers. Subsequent parse calls dereference these freed objects, causing segmentation faults. This issue has been addressed and fixed in version 3.17.2.
Potential Impact
Exploitation of this vulnerability can cause a segmentation fault in applications using vulnerable versions of the Oj gem, potentially leading to denial of service. There is no indication of code execution or data corruption beyond the crash. The CVSS 4.0 base score is 6.3 (medium severity), reflecting network attack vector, low attack complexity, no privileges required, no user interaction, and limited impact to availability.
Mitigation Recommendations
Upgrade to Oj version 3.17.2 or later, where this Use-After-Free vulnerability is fixed. No other mitigations are indicated or required.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-16T13:49:33.555Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a445a0927e9c7971999d89d
Added to database: 07/01/2026, 00:06:33 UTC
Last enriched: 07/01/2026, 00:21:59 UTC
Last updated: 07/01/2026, 00:21:59 UTC
Views: 2
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