CVE-2026-54899: medium-severity vulnerability in ohler55 oj
Oj: Use-After-Free in Oj::Parser Symbol Key Cache Toggle
Published · Updated
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.3epss 0.3%
exploitation probability
0.3%top 74% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N
Affected products
ohler55 · ojRelated CVEs — ohler55 oj
In the same product, most dangerous first.
CVE-2026-54900MEDIUMOj: Negative-Size memcpy in Oj::Parser create_id Attribute HandlingEPSS 0.4%CVE-2026-54902MEDIUMOj: Use-After-Free in Oj::Parser SAJ Long Key CallbackEPSS 0.4%CVE-2026-54502MEDIUMOj: Stack Buffer Overflow in Oj.dump via Large IndentEPSS 0.3%CVE-2026-54903MEDIUMOj: Integer Overflow in Oj.load 2GB String HandlingEPSS 0.3%CVE-2026-54901MEDIUMOj: Use-After-Free in Oj::Parser array_class/hash_class GC MarkingEPSS 0.3%CVE-2026-54592HIGHOj: Stack Buffer Overflow in Oj::Doc#each_child via Deeply Nested InputEPSS 0.3%