CVE-2026-40347

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Source
https://cve.org/CVERecord?id=CVE-2026-40347
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-40347.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-40347
Aliases
Downstream
Related
Published
2026-04-17T23:56:50.777Z
Modified
2026-06-18T03:54:26.511066413Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
Summary
Python-Multipart affected by Denial of Service via large multipart preamble or epilogue data
Details

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.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-400",
        "CWE-834"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40347.json"
}
References

Affected packages

Git / github.com/kludex/python-multipart

Affected ranges

Type
GIT
Repo
https://github.com/kludex/python-multipart
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
28f47859b4a40c2e11e02dc514b2e9743ceedd2e
Database specific 
{
    "cpe": "cpe:2.3:a:fastapiexpert:python-multipart:*:*:*:*:*:python:*:*",
    "source": [
        "AFFECTED_FIELD",
        "CPE_RANGE",
        "REFERENCES"
    ],
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "0.0.26"
        },
        {
            "introduced": "0"
        },
        {
            "fixed": "0.0.26"
        }
    ]
}

Affected versions

0.*
0.0.10
0.0.11
0.0.12
0.0.13
0.0.14
0.0.15
0.0.16
0.0.17
0.0.18
0.0.19
0.0.2
0.0.20
0.0.21
0.0.22
0.0.23
0.0.24
0.0.25
0.0.4
0.0.5
0.0.6
0.0.7
0.0.8
0.0.9

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-40347.json"