CVE-2022-31117Medium· 5.9▾ SunlitPotential double free of buffer during string decoding
▾ Sunlit zone — Low / medium · no exploitation signal
impact 32.5 · likelihood 0.4 · exploitation 0
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Exploit-prediction probability, daily snapshots since Jul 8.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via OSV
Last analysed / modified upstream
1.7%
1.7% → 1.9%
What kind of vulnerability is it? Who is impacted?
When an error occurs while reallocating the buffer for string decoding, the buffer gets freed twice.
Due to how UltraJSON uses the internal decoder, this double free is impossible to trigger from Python.
Has the problem been patched? What versions should users upgrade to?
Users should upgrade to UltraJSON 5.4.0.
Is there a way for users to fix or remediate the vulnerability without upgrading?
There is no workaround.
If you have any questions or comments about this advisory:
ujson < 5.4.0Upgrade to a patched release:
ujson 5.4.0Connected by shared product, vendor, weakness, or advisory.
CVE-2022-31116High· 7.5Incorrect handling of invalid surrogate pair characters
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CVE-2026-54911Medium· 6.5UltraJSON: Malformed/Truncated UTF-8 Accepted and Silently Rewritten in ujson.dumps()