CVE-2026-40347Disclosure(fastapiexpert / python-multipart)

LOWCVSS 5.3 · MEDIUM

Signal is active with 2 mentions in latest observed window

Immediate actions

  • Track advisory updates for patch or workaround availability

Recommended action window: Monitor and triage in normal cycle

NVD 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.

0.0/ 10 priority

Sources & remediation

Weakness type (CWE)
CWE-400CWE-834

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

NONE

Momentum

STABLE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • python-multipart

Threat summary

  • 3 mentions across 2 observed days
  • Momentum state: stable

What's happening

  • Technical details provided in 3 signals
  • Disclosure: 3 classified signals
  • Peaked at 2 mentions on most recent observed day (2026-04-18)
  • 3 total mentions across 2 days

Affected systems

Products
python-multipart

Deep dive

Activity timeline3 mentions / 2d
01122Mentions · 2026-04-16: 1Mentions · 2026-04-18: 2Technical Details · 2026-04-16: 1Technical Details · 2026-04-18: 204-1604-18
Signal classification1 categories
Disclosure
3100.0%
Referenced assets3 URLs
Classification over time
DateTotalLabels
2026-04-161
Disclosure1
2026-04-182
Disclosure2
Full discourse3 posts
  • CVE@CVEnew
    Disclosure

    CVE-2026-40347 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… https://www.cve.org/CVERecord?id=CVE-2026-40347

    Post summary

    The text announces a denial‑of‑service flaw (CVE‑2026‑40347) affecting Python‑Multipart versions below 0.0.26, but provides no PoC, exploit, or patch details.

    0000075
    57.2K followersView on X
  • Vulmon Vulnerability Feed@VulmonFeeds
    Disclosure

    CVE-2026-40347 Denial of Service Vulnerability in Python-Multipart Versions Prior to 0.0.26 https://vulmon.com/vulnerabilitydetails?qid=CVE-2026-40347

    Post summary

    The message announces a denial‑of‑service flaw in Python‑Multipart versions before 0.0.26, linking to a database entry but providing no PoC, exploit code, or patch details.

    0000035
    4.0K followersView on X
  • DailyCVE@dailycve
    Disclosure

    🟠 #python-multipart, Denial of Service (DoS), #CVE-2026-40347 (Moderate) https://dailycve.com/python-multipart-denial-of-service-dos-cve-2026-40347-moderate/

    Post summary

    A moderate‑severity DoS vulnerability (CVE-2026-40347) in python‑multipart is announced, but the brief notice offers no details on exploitation, patching, or PoC evidence.

    0000032
    181 followersView on X
CPE platform detail1 entries

1 of 1 entries

PartVendorProductVersionTarget SWTarget HW
Appfastapiexpertpython-multipart-python-

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