CVE-2026-54696
Ruby JSON: JSON generator heap buffer overflow when streaming to an IO
Vexday Risk Score
8Low
SSVC decision (CISA)
Track
No exploitation signal → monitor
CVSS 3.7EPSS 0.3%KEV nãoPoC —Nuclei —Metasploit —Patch —
Lifecycle
30 Jun 2026Published on NVD
Recommendation: Monitor — no exploitation signal at the moment.
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.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
Affected products
ruby · jsonWant to know if your infrastructure is exposed to this?
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