Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.2, when in object mode, Oj.dump is vulnerable to a heap buffer overflow when serializing Exception objects with a large :indent value. The serializer allocates a buffer sized for the object's attributes but does not account for the indent bytes added on each write. With indent: 5000, the accumulation of 5,000-byte indent strings overflows the 13,150-byte heap allocation, corrupting adjacent heap memory. This issue has been fixed in version 3.17.2.
CVE-2026-54896
LOWPre-NVD 2.12.1—Trending — 3 sources updated this week
EchelonGraph scoreMEDIUM confidence
This low-severity CVE scores 2.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.1%, top 98% 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).
Triggered by: NVD CVSS baseline
Sources: epss, secondary
2.1
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 2.1Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 2.1
- EG Score
- 2.1(medium)
- EPSS
- 2.1%
- KEV
- Not listed
Published
June 19, 2026
Last Modified
July 1, 2026
References (2)
- security-advisories@githubhttps://github.com/ohler55/oj/security/advisories/GHSA-35w3-pjm6-wj95
- 134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/ohler55/oj/security/advisories/GHSA-35w3-pjm6-wj95
Vendor Advisories for CVE-2026-54896(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
RubyGems(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| oj | 0.5 ... 3.9.2 (294 versions) | 3.17.3 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 11× in last 7d / 12× 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.
- 2026-07-06 23:26 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
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-04 00:25 UTCEG score recompute
- 2026-07-01 15:07 UTCEPSS rescore
- 2026-07-01 01:24 UTCEG score recompute▲ 2.10
- 2026-07-01 01:19 UTCNVD updateCVSS v3 → 2.1 · CVSS v4 → 2.1 · severity → LOW
- 2026-06-19 20:22 UTCEG score recompute
Related CVEs(same CWE)
Same CWE
10 shownCWE-122
Frequently asked(5)
What is CVE-2026-54896?
CVE-2026-54896 is a low vulnerability published on June 19, 2026. Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.2, when in object mode, Oj.dump is vulnerable to a heap buffer overflow when serializing Exception objects with a large :indent value. The serializer allocates a buffer sized for the…
When was CVE-2026-54896 disclosed?
CVE-2026-54896 was first published in the National Vulnerability Database on June 19, 2026, with the most recent update on July 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54896 actively exploited?
CVE-2026-54896 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-54896?
CVE-2026-54896 has a CVSS v3 base score of 2.1 (NVD).
How do I remediate CVE-2026-54896?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54896, 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
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-54896
Is Your Infrastructure Affected by CVE-2026-54896?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.