CVE-2026-54899
Medium
Description
Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. Prior to version 3.17.2, disabling symbol_keys on a reused Oj::Parser instance triggers a heap use-after-free. When symbol_keys is toggled from true to false, opt_symbol_keys_set frees the internal key cache (cache_free) but does not clear the pointer. The next parse call reads from the freed cache via cache_intern, producing a use-after-free. This issue has been fixed in version 3.17.2.
SeverityMedium
CVSS6.3
Exploit probability—
ProductOhler55 Oj
PublishedJul 1, 2026
First seenJul 1, 2026
Weakness typeCWE-416Use after free
How to fix
Sources list no fixed version or patch link for this vulnerability.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| ohler55 oj | < 3.17.2 | — |
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