CVE-2026-54903: medium-severity vulnerability in ohler55 oj
Oj: Integer Overflow in Oj.load 2GB String Handling
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. In versions prior to 3.17.2, Oj.load is vulnerable to heap corruption when parsing a JSON string longer than 2 GB. An integer overflow in buf_append_string (buf.h:61) converts the string length to a large negative size_t, causing memcpy to copy an astronomically large amount of data out of bounds. This crashes the process and can corrupt adjacent heap memory. The issue has been fixed in version 3.17.2.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/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-2026-54901MEDIUMOj: Use-After-Free in Oj::Parser array_class/hash_class GC MarkingEPSS 0.3%CVE-2026-54899MEDIUMOj: Use-After-Free in Oj::Parser Symbol Key Cache ToggleEPSS 0.3%CVE-2026-54592HIGHOj: Stack Buffer Overflow in Oj::Doc#each_child via Deeply Nested InputEPSS 0.3%