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.
CVE-2026-54696
This low-severity CVE scores 3.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 78% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 3.7
- EG Score
- 3.7(medium)
- EPSS
- 21.9%
- KEV
- Not listed
Published
June 30, 2026
Last Modified
July 2, 2026
References (3)
- security-advisories@githubhttps://github.com/ruby/json/releases/tag/v2.19.9
- security-advisories@githubhttps://github.com/ruby/json/security/advisories/GHSA-x2f5-4prf-w687
- 134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/ruby/json/security/advisories/GHSA-x2f5-4prf-w687
Weakness Classification(3)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 16× in last 7d / 22× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-11 08:27 UTCEPSS rescore
- 2026-07-11 08:27 UTCEPSS rescore
- 2026-07-09 23:17 UTCEG score recompute
- 2026-07-09 19:10 UTCEPSS rescore
- 2026-07-09 19:10 UTCEPSS rescore
- 2026-07-08 15:16 UTCEPSS rescore
- 2026-07-08 15:16 UTCEPSS rescore
- 2026-07-07 13:46 UTCEPSS rescore
- 2026-07-07 13:46 UTCEPSS rescore
- 2026-07-07 00:00 UTCEG score recompute
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-05 02:31 UTCEPSS rescore
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-04 00:43 UTCEG score recompute
- 2026-07-01 15:07 UTCEPSS rescore
- 2026-07-01 01:23 UTCEG score recompute
- 2026-07-01 01:19 UTCNVD updatefirst tracked
Related CVEs(same CWE)
Same CWE
10 shownCWE-122 · CWE-787 · CWE-131
- CVE-2006-10003EG 9.8CRITICAL
- CVE-2007-0158EG 9.8CRITICAL
- CVE-2007-0899EG 9.8CRITICAL
- CVE-2004-1363EG 9.8EPSS 95%CRITICAL
- CVE-2004-0434EG 9.8EPSS 94%CRITICAL
- CVE-2003-0899EG 9.8EPSS 97%CRITICAL
- CVE-2002-1347EG 9.8EPSS 93%CRITICAL
- CVE-2001-0248EG 9.8EPSS 95%CRITICAL
- CVE-2001-0249EG 9.8EPSS 97%CRITICAL
- CVE-2010-20115EG 9.3CRITICAL
Frequently asked(5)
What is CVE-2026-54696?
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How do I remediate CVE-2026-54696?
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