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Fencer Vulns
high 8.0

CVE-2023-46136 json

Werkzeug vulnerable to high resource usage when parsing multipart/form-data containing a large part with CR/LF character at the beginning

published 2023-10-24 3 y ago modified 2026-09-10 1 mo ago also GHSA-hrfv-mqp8-q5rw , PYSEC-2023-221 , EUVD-2023-0280

cvss
8.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.3%
EPSS 1.3% chance of exploitation in 30 days, percentile 70%
public exploits
0
none known

Summary

Werkzeug is a comprehensive WSGI web application library. In versions on the 3.x branch prior to 3.0.1 and on the 2.x branch prior to 2.3.8, if an upload of a file that starts with CR or LF and then is followed by megabytes of data without these characters: all of these bytes are appended chunk by chunk into internal bytearray and lookup for boundary is performed on growing buffer. This allows an attacker to cause a denial of service by sending crafted multipart data to an endpoint that will parse it. The amount of CPU time required can block worker processes from handling legitimate requests. This vulnerability has been patched in version 3.0.1 and 2.3.8.

Patch / fix

  • pypi werkzeug 2.3.8, 3.0.1
  • palletsprojects werkzeug 2.3.8
  • python-werkzeug Debian 12 2.2.2-3+deb12u1
  • python-werkzeug Debian 14, Debian 13 3.0.1-2

debian advisories DEBIAN-CVE-2023-46136

  • ceph ceph storage 8.1 2:19.2.1-222.el9cp
  • cephadm ceph storage 8.1 2:19.2.1-222.el9cp
  • liboath ceph storage 8.1 2.6.12-1.el9cp
  • librbd1 ceph storage 8.1 2:19.2.1-222.el9cp
  • librgw2 ceph storage 8.1 2:19.2.1-222.el9cp
  • rbd-nbd ceph storage 8.1 2:19.2.1-222.el9cp
  • ceph-mib ceph storage 8.1 2:19.2.1-222.el9cp
  • ceph-base ceph storage 8.1 2:19.2.1-222.el9cp

red hat advisories RHSA-2025:9775RHSA-2023:7610RHSA-2024:0214RHSA-2024:0189RHSA-2023:7473RHSA-2023:7477

  • python-Werkzeug SLE Module for Python 3 15 SP5, SLE Module for Python 3 15 SP4, openSUSE Leap 15.5 +1 more 2.3.6-150400.6.6.1

suse advisories SUSE-SU-2023:4288-1

  • python-Werkzeug openSUSE Tumbleweed 3.1.9-1.1
  • python-Werkzeug openSUSE Tumbleweed 3.0.1-1.1

opensuse advisories openSUSE-SU-2026:11943-1openSUSE-SU-2024:13375-1

  • py3-werkzeug Alpine 3.24, Alpine 3.23, Alpine 3.22 +4 more 2.3.7-r0

alpine advisories ALPINE-CVE-2023-46136

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • python-werkzeug CBL-Mariner 2.0 2.3.7-1
  • python-werkzeug Azure Linux 3.0 3.0.1-1

azure linux advisories AZL-31701AZL-35141

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-46136 updated cvss 7.5

python-werkzeug: high resource consumption leading to denial of service

  • Red Hat Ceph Storage 5 python-werkzeug, python3-werkzeug
    affected: no fix available
  • Red Hat Ceph Storage 6 python-werkzeug
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux 7 python-werkzeug
    affected: no fix planned “Out of support scope”
  • Red Hat OpenStack Platform 16.1 python-werkzeug, python3-werkzeug Red Hat OpenStack Platform 16.2 python-werkzeug, python3-werkzeug, python3-designate, openstack-designate-api, openstack-designate-mdns, openstack-designate-sink, +5 more
    affected: no fix planned “Will not fix”
  • Red Hat OpenStack Platform 18.0 python-httpcore, python-werkzeug Red Hat Quay 3 quay/quay-rhel8
    affected: no fix available
  • Red Hat Storage 3 python-werkzeug
    affected: no fix planned “Will not fix”
  • Red Hat Ironic content for Red Hat OpenShift Container Platform 4.12 python-werkzeug 2.0.3-5.el9, python3-werkzeug 2.0.3-5.el9
    fixed: vendor fix RHSA-2023:7610
  • Red Hat Ironic content for Red Hat OpenShift Container Platform 4.13 python-werkzeug 2.0.3-5.el9, python3-werkzeug 2.0.3-5.el9
    fixed: vendor fix RHSA-2023:7477
show 4 more
  • Red Hat Ironic content for Red Hat OpenShift Container Platform 4.14 python-werkzeug 2.2.3-2.el9, python3-werkzeug 2.2.3-2.el9
    fixed: vendor fix RHSA-2023:7473
  • Red Hat Ceph Storage 8.1 Tools liboath 2.6.12-1.el9cp, oath-toolkit 2.6.12-1.el9cp
    fixed: vendor fix RHSA-2025:9775
  • Red Hat OpenStack Platform 17.1 python-werkzeug 2.0.1-6.el9ost, python-werkzeug 2.0.1-8.el8ost, python3-werkzeug 2.0.1-6.el9ost, python3-werkzeug 2.0.1-8.el8ost
    fixed: vendor fix RHSA-2024:0189
  • Red Hat Ironic content for Red Hat OpenShift Container Platform 4.13 python-eventlet 0.33.1-5.el9, python3-eventlet 0.33.1-5.el9 Red Hat Ironic content for Red Hat OpenShift Container Platform 4.14 python-eventlet 0.33.1-5.el9, python-markupsafe 2.1.1-4.el9, python3-eventlet 0.33.1-5.el9, python3-markupsafe 2.1.1-4.el9 Red Hat Ceph Storage 8.1 Tools ceph 19.2.1-222.el9cp, cephadm 19.2.1-222.el9cp, librbd1 19.2.1-222.el9cp, librgw2 19.2.1-222.el9cp, rbd-nbd 19.2.1-222.el9cp, ceph-mib 19.2.1-222.el9cp, +18 more Red Hat Enterprise Linux 8 python3-werkzeug Red Hat OpenShift Container Platform 4.12 perf 4.18.0-372.82.1.el8_6, kernel 4.18.0-372.82.1.el8_6, bpftool 4.18.0-372.82.1.el8_6, kernel-core 4.18.0-372.82.1.el8_6, kernel-tools 4.18.0-372.82.1.el8_6, python3-perf 4.18.0-372.82.1.el8_6, +41 more Red Hat OpenShift Container Platform 4.13 openshift 4.13.0-202311212009.p0.gaa37255.assembly.stream.el8, openshift 4.13.0-202311212009.p0.gaa37255.assembly.stream.el9, openshift-hyperkube 4.13.0-202311212009.p0.gaa37255.assembly.stream.el8, openshift-hyperkube 4.13.0-202311212009.p0.gaa37255.assembly.stream.el9
    +1 more products
    Red Hat OpenShift Container Platform 4.14 haproxy 2.6.13-2.rhaos4.14.el8, haproxy26 2.6.13-2.rhaos4.14.el8, cri-o 1.27.2-2.rhaos4.14.git9d684e2.el8, cri-o 1.27.2-2.rhaos4.14.git9d684e2.el9, openshift 4.14.0-202311161233.p0.gd548052.assembly.stream.el8, openshift 4.14.0-202311161233.p0.gd548052.assembly.stream.el9, +2 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.29% chance of exploitation in the next 30 days, higher than 70% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.0 CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 5.7 CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
pypi werkzeug
>=3.0.0, <3.0.1
>=2.0.0rc1, <2.3.8
<2.3.8
3.0.1
2.3.8

Affected products

  • pallets werkzeug

Classification

Weakness
  • CWE-407 Inefficient Algorithmic Complexity
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-787 Out-of-bounds Write

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.