CVE-2026-54696: 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 obj

lowCVSS 3.7CVE-2026-54696

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.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: low — CVSS 3.7
Published: 2026-06-30
Last updated: 2026-07-02
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-54696

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-546960.30% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 22% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-54696	coverage & exploitation status	NVD · CVE.org

Recent advisories for Ruby JSON is

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

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unknownCVE-2026-54899: Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. Prior to ve…nvd · 2026-07-01
unknownCVE-2026-54898: Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions…nvd · 2026-07-01

CVE-2026-54696: 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 obj

Details

Exploitation outlook

Referenced CVEs

Recent advisories for Ruby JSON is

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