UltraJSON has a Memory Leak in ujson.dump() on Write Failure — CVE-2026-44660

Summary

### Summary 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. Code that uses `ujson.dumps()` rather than `ujson.dump()` or only JSON load/decode methods is unaffected. ### Details **Vulnerability Location:** -…

Product

pip: ujson

What to do

General, cautious steps (verify details in the official source):

• Prioritize patching or mitigation immediately (treat as actively risky).
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

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