Medium
python-multipart — security advisory
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.
- Products
- python-multipart
- Affected versions
- 0.0.20-1, 0.0.20-1.1, 0.0.26-1, 0.0.32-1, 0.0.5-2, 0.0.5-2ubuntu0.1~esm1, 0.0.5-3, 0.0.6-1, 0.0.9-1, 0.0.9-1ubuntu0.1~esm1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-40347
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 02:44 UTC · Revision 1
Source evidence
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.
osv:UBUNTU-CVE-2026-40347
python-multipart
Fixed versions: Not specified
python-multipart
Fixed versions: Not specified
python-multipart
Fixed versions: Not specified
python-multipart
Fixed versions: Not specified
python-multipart
Fixed versions: Not specified
Complete source record
{
"id": "c46eae62ce77197c2c02753cf0f8a47c47d8d84b14dbc17fe8f50807b51523ca",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-40347",
"method": "structured",
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"title": "UBUNTU-CVE-2026-40347",
"summary": "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.",
"evidence": "osv:UBUNTU-CVE-2026-40347",
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"modified": "2026-10-17T12:58:54.296443724Z",
"provider": "osv",
"upstream": [
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],
"references": [
"https://ubuntu.com/security/CVE-2026-40347",
"https://www.cve.org/CVERecord?id=CVE-2026-40347",
"https://github.com/Kludex/python-multipart/security/advisories/GHSA-mj87-hwqh-73pj",
"https://github.com/Kludex/python-multipart/pull/259"
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"severity_evidence": "/severity/0/score"
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"source_id": "core-osv",
"document_id": 359155,
"published_at": "2026-04-18T00:16:00+00:00"
}