CVE-2026-33210

CRITICALNVD 9.19.1
EchelonGraph scoreLOW confidence

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). 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).

Triggered by: NVD CVSS baseline
Sources: nvd
9.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 9.1Exploit: NoneExposed: 0

A fix is available — apply it.

Ruby JSON is a JSON implementation for Ruby. From version 2.14.0 to before versions 2.15.2.1, 2.17.1.2, and 2.19.2, a format string injection vulnerability can lead to denial of service attacks or information disclosure, when the allow_duplicate_key: false parsing option is used to parse user supplied documents. This issue has been patched in versions 2.15.2.1, 2.17.1.2, and 2.19.2.

CVSS v3
9.1
EG Score
9.1(low)
EPSS
53.5%
KEV
Not listed

Published

March 20, 2026

Last Modified

June 30, 2026

Advisory Details (6)

Auto-updated Jun 30, 2026
Patch available. Sources: github, redhat.
redhat Patch Available

Affected: Red Hat Enterprise Linux 10",

https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33210.json
redhat Patch Available

2449871 – (CVE-2026-33210) CVE-2026-33210 ruby/json: Ruby JSON: Denial of Service or Information Disclosure via format string injection

Affected: Red Hat Enterprise Linux 10

https://bugzilla.redhat.com/show_bug.cgi?id=2449871
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-33210
redhat Patch Available

Affected: Red Hat Enterprise Linux 10.

https://access.redhat.com/errata/RHSA-2026:20606
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.

https://access.redhat.com/errata/RHSA-2026:20596
github Patch Available

Format string injection vulnerability · Advisory · ruby/json · GitHub

https://github.com/ruby/json/security/advisories/GHSA-3m6g-2423-7cp3

Vendor Advisories for CVE-2026-33210(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatruby4.0-0:4.0.3-34.el10_22026-05-26redhat
redhatruby:4.0-9080020260513131334.92026-05-26redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
RubyGems(1)
PackageVulnerable rangeFixed inDependents
json2.18.0, 2.18.1, 2.19.0, 2.19.12.19.2—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 15× 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.

  1. 2026-07-11 08:27 UTCEPSS rescore
  2. 2026-07-09 19:10 UTCEPSS rescore
  3. 2026-07-08 15:15 UTCEPSS rescore
  4. 2026-07-07 13:46 UTCEPSS rescore
  5. 2026-07-06 16:27 UTCEPSS rescore
  6. 2026-07-06 16:27 UTCEPSS rescore
  7. 2026-07-06 02:23 UTCEPSS rescore
  8. 2026-07-06 02:23 UTCEPSS rescore
  9. 2026-07-05 02:30 UTCEPSS rescore
  10. 2026-07-04 06:31 UTCEPSS rescore
  11. 2026-07-01 15:06 UTCEPSS rescore
  12. 2026-06-30 23:22 UTCEPSS rescore
  13. 2026-06-30 04:33 UTCEG score recompute
  14. 2026-06-30 04:33 UTCVendor advisory
  15. 2026-06-30 04:32 UTCNVD updatefirst tracked

Frequently asked(5)

What is CVE-2026-33210?
CVE-2026-33210 is a critical vulnerability published on March 20, 2026. Ruby JSON is a JSON implementation for Ruby. From version 2.14.0 to before versions 2.15.2.1, 2.17.1.2, and 2.19.2, a format string injection vulnerability can lead to denial of service attacks or information disclosure, when the allowduplicatekey: false parsing option is used to parse user…
When was CVE-2026-33210 disclosed?
CVE-2026-33210 was first published in the National Vulnerability Database on March 20, 2026, with the most recent update on June 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-33210 actively exploited?
CVE-2026-33210 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 53.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-33210?
CVE-2026-33210 has a CVSS v3 base score of 9.1 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-33210?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-33210, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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