CVE-2026-54896

Oj Optimized JSON is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.2, when in object mode, Oj.dump is vulnerable to a heap buffer overflow when serializing Exception objects with a large :indent value. The serializer allocates a buffer sized for the object'...

CVE-2026-54592

The CVE-2026-54592 vulnerability affects Oj (Optimized JSON), a Ruby gem JSON parser/marshaller. In versions prior to 3.17.3, Oj::Doc#each_child can overflow a fixed-size stack buffer when recursively traversing deeply nested JSON, causing a DoS. The issue arises from a two-step chain in ext/oj/f...

CVE-2026-54592 Oj: Stack Buffer Overflow in Oj::Doc#each_child via Deeply Nested Input

Oj Optimized JSON is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.3, Oj::Doceachchild, when invoked recursively over a deeply nested JSON document, overflows a fixed-size stack buffer and aborts the process, leading to DoS. In a two-step chain in...

CVE-2026-54592 Oj: Stack Buffer Overflow in Oj::Doc#each_child via Deeply Nested Input

Oj Optimized JSON is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.3, Oj::Doceachchild, when invoked recursively over a deeply nested JSON document, overflows a fixed-size stack buffer and aborts the process, leading to DoS. In a two-step chain in...

CVE-2026-54502

Oj Optimized JSON is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.2, Oj.dump is vulnerable to a stack-based buffer overflow when a large :indent value is provided by the developer. fillindent in dump.h calls memsetindentstr, ' ', sizetopts-indent without...

CVE-2026-54502

Oj Optimized JSON is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.2, Oj.dump is vulnerable to a stack-based buffer overflow when a large :indent value is provided by the developer. fillindent in dump.h calls memsetindentstr, ' ', sizetopts-indent without...

CVE-2026-54502

Oj (Optimized JSON) is a Ruby gem that provides a JSON parser and object marshaller. Vulnerability: in versions prior to 3.17.2, Oj.dump can trigger a stack-based buffer overflow when a very large indent value is used. The root cause is fill_indent in dump.h calling memset(indent_str, ' ', (size_...

CVE-2026-54500

Oj (Optimized JSON) is a Ruby gem for JSON parsing/ marshalling. Affects versions prior to 3.17.3 where Oj.load in mode :object reads uninitialized stack memory when a JSON object has a long key (254+ bytes). In ext/oj/intern.c, form_attr() passes an uninitialized stack buffer to rb_intern3(), ca...

CVE-2026-54500 Oj: intern.c form_attr has an uninitialized stack read

Oj Optimized JSON is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.3, Oj.load in :object mode reads uninitialized stack memory and, for long keys, reads out of bounds when parsing a JSON object whose key is 254 bytes or longer. The interned bytes can surfac...

CVE-2026-54500 Oj: intern.c form_attr has an uninitialized stack read

Oj Optimized JSON is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.3, Oj.load in :object mode reads uninitialized stack memory and, for long keys, reads out of bounds when parsing a JSON object whose key is 254 bytes or longer. The interned bytes can surfac...

CVE-2026-54500

Oj Optimized JSON is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.3, Oj.load in :object mode reads uninitialized stack memory and, for long keys, reads out of bounds when parsing a JSON object whose key is 254 bytes or longer. The interned bytes can surfac...

CVE-2026-54899 Oj: Use-After-Free in Oj::Parser Symbol Key Cache Toggle

Oj Optimized JSON is a JSON parser and Object marshaller packaged as a Ruby gem. Prior to version 3.17.2, disabling symbolkeys on a reused Oj::Parser instance triggers a heap use-after-free. When symbolkeys is toggled from true to false, optsymbolkeysset frees the internal key cache cachefree but...

CVE-2026-54899

Oj (Optimized JSON) is a Ruby gem for JSON parsing/marshalling. Prior to 3.17.2, disabling symbol_keys on a reused Oj::Parser can cause a heap use-after-free when toggling symbol_keys from true to false: opt_symbol_keys_set frees the internal key cache but does not clear the pointer, so the next ...

CVE-2026-54899

Oj Optimized JSON is a JSON parser and Object marshaller packaged as a Ruby gem. Prior to version 3.17.2, disabling symbolkeys on a reused Oj::Parser instance triggers a heap use-after-free. When symbolkeys is toggled from true to false, optsymbolkeysset frees the internal key cache cachefree but...

GHSA-475M-PH3X-64GP Oj: Integer Overflow in Oj.load 2GB String Handling

Summary Oj.load is vulnerable to heap corruption when parsing a JSON string longer than 2 GB. An integer overflow in bufappendstring buf.h:61 converts the string length to a large negative sizet, causing memcpy to copy an astronomically large amount of data out of bounds. This crashes the process...

Use After Free

Overview Affected versions of this package are vulnerable to Use After Free in the Oj::Parser when operating in SAJ mode with object keys of 35 bytes or longer. An attacker can cause a segmentation fault by triggering garbage collection within a callback, leading to use of a freed memory pointer...

Oj: Use-After-Free in Oj::Parser SAJ Long Key Callback

Summary Oj::Parser in SAJ mode does not protect cached object keys ≥ 35 bytes from garbage collection. A Ruby callback that triggers GC inside hashend can cause the key string to be reclaimed while the C parser still holds a pointer to it. The subsequent access to the freed string VALUE results i...

GHSA-VWM4-62GF-X745 Oj: Use-After-Free in Oj::Parser array_class/hash_class GC Marking

Summary Oj::Parser in usual mode does not mark arrayclass and hashclass references during garbage collection. If GC runs after the class is assigned but before a parse, the class object is reclaimed, leaving the parser holding a dangling VALUE. The subsequent parse call dereferences the freed...

Oj: Negative-Size memcpy in Oj::Parser create_id Attribute Handling

Summary Oj::Parserparse in usual mode with createid enabled is vulnerable to heap corruption via a negative-size memcpy. When a JSON object key is exactly 65,535 bytes long, an integer truncation in formattr usual.c:63 converts the length to -1 before passing it to memcpy. This causes memcpy to...

GHSA-9CV6-QCJW-4GRX Oj: Negative-Size memcpy in Oj::Parser create_id Attribute Handling

Summary Oj::Parserparse in usual mode with createid enabled is vulnerable to heap corruption via a negative-size memcpy. When a JSON object key is exactly 65,535 bytes long, an integer truncation in formattr usual.c:63 converts the length to -1 before passing it to memcpy. This causes memcpy to...