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CVE-2026-53540

Status: AnalyzedLow (3.7)—

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.31, parse_form() did not validate the Content-Length header before using it to bound its chunked read of the request body. A negative Content-Length turned the bounded read into a read-until-EOF, so the entire body was loaded into memory in a single read instead of in fixed-size chunks. This vulnerability is fixed in 0.0.31.

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

Fastapiexpert — Python-multipart

CWEs

References

Raw JSON (NVD)

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          "timestamp": "2026-06-22T17:21:49.069742Z"
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          "userInteraction": "NONE",
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  "lastModified": "2026-06-26T19:50:18.340",
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