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CVE PROGRAM SOURCE RECORD8.7 High

CVE-2026-44660

UltraJSON: Memory Leak in ujson.dump() on Write Failure

Description

UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Prior to 5.12.1, when ujson.dump() writes to a file-like object and the write operation raises an exception, the serialized JSON string object is not decremented, leaking memory. Each failed write operation leaks the full size of the serialized payload. This vulnerability is fixed in 5.12.1.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

ultrajson ultrajson

  • < 5.12.1affected

References