CVE-2026-54897

CVE-2026-54897 is a low-severity vulnerability with a CVSS 4.0 base score of 2.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-416.

Key facts

Description

Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. Prior to 3.17.2, Oj::Doc iterators (each_value, each_child, each_leaf) were vulnerable to a heap use-after-free. When a Ruby block yielded during iteration calls doc.close or d.close, the document's heap memory is freed while the C iterator is still running. When control returns from the block, the iterator reads from the freed region, producing a use-after-free accessible from pure Ruby. This issue has been fixed in version 3.17.2.

Frequently asked questions

What is CVE-2026-54897?
Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. Prior to 3.17.2, Oj::Doc iterators (each_value, each_child, each_leaf) were vulnerable to a heap use-after-free. When a Ruby block yielded during iteration calls doc.close or d.close, the document's heap memory is freed while the C iterator is still running. When control returns from the block, the iterator reads from the freed region, producing a use-after-free accessible from pure Ruby. This issue has been fixed in version 3.17.2.
How severe is CVE-2026-54897?
CVE-2026-54897 has a CVSS 4.0 base score of 2.1, rated low severity.
Is CVE-2026-54897 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-54897?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-54897 published?
CVE-2026-54897 was published on 2026-07-01.

References

Other CWE-416 (Use After Free) vulnerabilities

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