CVE•Published 2026-04-18•Modified 2026-04-24•0 articles on news•5 live references•NVD data

CVE-2026-40347Fastapiexpert · Python-multipart

Vulnerability data via NVD (ingested)

CVSS v3.1

5.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS percentile

Exploit Prediction Scoring System · top 97% of all CVEs

Weaknesses (CWE)

CWE-400Uncontrolled Resource Consumption CWE-834Excessive Iteration

Description

Python-Multipart is a streaming multipart parser for Python. Versions prior to 0.0.26 have a denial of service vulnerability when parsing crafted `multipart/form-data` requests with large preamble or epilogue sections. Upgrade to version 0.0.26 or later, which skips ahead to the next boundary candidate when processing leading CR/LF data and immediately discards epilogue data after the closing boundary.

Timeline

Published 2026-04-18

Modified 2026-04-24

External references

NVD MITRE Exploit-DB Sploitus VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2026-40347

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Fastapiexpert Python-multipart"

All exposed Fastapiexpert Python-multipart instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Python-multipart"

HTTP body or banner mentions "Python-multipart" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-40347