CVE-2026-54897

Oj : Use-After-Free in Oj::Doc Iterators via Reentrant Close

LOW
2.1
CVSS Score
Published: June 30, 2026 at 11:22 PM UTC
Updated: October 25, 2026 at 05:10 PM UTC
1 product affected across 1 vendorOj

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Severity
LOW2.1
Exploit prediction
EPSS 0.2%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 3.17.2
Affected range stops below 3.17.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

2.1LOWGitHub_M
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-416

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