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CVE-2026-40347

CVE-2026-40347 · Python-Multipart affected by Denial of Service via large multipart preamble or epilogue data

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 5.3 · Medium · EPSS 0.4% · Fix available

Published
Updated

Stack: system · python

Affected products and versions

  • python-multipart

    Versions
    • < 0.0.26: Affected

    No fix published

  • python-multipart Debian:12

    Versions
    • 0.0.17-1
    • 0.0.17-2
    • 0.0.17-3
    • 0.0.17-4
    • 0.0.17-5
    • 0.0.20-1
    • 0.0.20-1.1
    • 0.0.20-1.1~deb13u1
    • 0.0.22-1
    • 0.0.26-1
    • 0.0.32-1
    • 0.0.5-3
    • 0.0.6-1
    • 0.0.9-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • python-multipart Debian:13

    Versions
    • 0.0.20-1
    • 0.0.20-1.1
    • 0.0.20-1.1~deb13u1
    • 0.0.22-1
    • 0.0.26-1
    • 0.0.32-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • python-multipart Debian:14

    Versions
    • 0.0.20-1
    • 0.0.20-1.1
    • 0.0.20-1.1~deb13u1
    • 0.0.22-1
    Affected ranges
    • ECOSYSTEM: < 0.0.26-1

    Update to 0.0.26-1

  • python-multipart PyPI

    Versions
    • 0.0.1
    • 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
    • 0.0.3
    • 0.0.4
    • 0.0.5
    • 0.0.6
    • 0.0.7
    • 0.0.8
    • 0.0.9
    Affected ranges
    • ECOSYSTEM: < 0.0.26

    Update to 0.0.26

  • python-multipart Ubuntu:Pro:22.04:LTS

    Versions
    • 0.0.5-2
    • 0.0.5-2ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • python-multipart Ubuntu:Pro:24.04:LTS

    Versions
    • 0.0.5-3
    • 0.0.6-1
    • 0.0.9-1
    • 0.0.9-1ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • python-multipart Ubuntu:25.10

    Versions
    • 0.0.20-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • python-multipart Ubuntu:26.10

    Versions
    • 0.0.20-1.1
    • 0.0.26-1
    • 0.0.32-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • python-multipart Ubuntu:26.04:LTS

    Versions
    • 0.0.20-1
    • 0.0.20-1.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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