CVE-2026-54696
Ruby JSON: JSON generator heap buffer overflow when streaming to an IO
CVSS Score
3.7
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-122 CWE-131 CWE-787 |
| Vendor | ruby |
| Product | json |
| Ecosystems | |
| Industries | Technology |
| Published | Jun 30, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low
Affected Versions
ruby / json
>= 2.9.0, < 2.19.9