Quick answers
- Is CVE-2026-54897 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-54897 being exploited in the wild.
- How severe is CVE-2026-54897?
- High severity, with a CVSS score of 4, published 1 July 2026.
- Which products and versions are affected?
- oj (RubyGems) < 3.17.2, ECOSYSTEM:introduced=0,fixed=3.17.3.
- Is there a fix for CVE-2026-54897?
- Yes. oj (RubyGems): upgrade to 3.17.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-54897 attacked?
- It is attacked with local access, in a software library.
- Am I affected by CVE-2026-54897?
- Check whether you run oj (RubyGems) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- oj (RubyGems): upgrade to 3.17.3 or later
bundle update oj
Technical details
A heap use-after-free vulnerability exists in the Oj::Doc iterators (each_value, each_child, and each_leaf) within ext/oj/fast.c. The issue occurs because rb_yield allows execution of arbitrary Ruby code during iteration; if the Ruby block calls doc.close or d.close, the document's backing heap memory is freed via ruby_sized_xfree. When control returns to the C iterator, it attempts to read the 'next' pointer from the now-freed memory region. This vulnerability is accessible from pure Ruby and has been addressed in version 3.17.2.
Affected products
- ohler55 oj < 3.17.2
Identifiers
- CVE-2026-54897
- GHSA-9ppp-w3g4-fh4q
Timeline
- 2026-06-16: advisory: GitHub Security Advisory published
- 2026-06-30: disclosed: CVE published to NVD
- 2026-07-01: other: Advisory updated