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Fencer Vulns
high 7.5

CVE-2025-47287 json

Tornado vulnerable to excessive logging caused by malformed multipart form data

published 2025-05-15 17 mo ago modified 2026-09-10 1 mo ago also EUVD-2025-15444 , GHSA-7cx3-6m66-7c5m , PYSEC-2026-1974

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 55%
public exploits
0
none known

Summary

Tornado is a Python web framework and asynchronous networking library. When Tornado's ``multipart/form-data`` parser encounters certain errors, it logs a warning but continues trying to parse the remainder of the data. This allows remote attackers to generate an extremely high volume of logs, constituting a DoS attack. This DoS is compounded by the fact that the logging subsystem is synchronous. All versions of Tornado prior to 6.5.0 are affected. The vulnerable parser is enabled by default. Upgrade to Tornado version 6.50 to receive a patch. As a workaround, risk can be mitigated by blocking `Content-Type: multipart/form-data` in a proxy.

Patch / fix

  • pypi tornado 6.5
  • tornadoweb tornado 6.5.0
  • python-tornado Debian 12 6.2.0-3+deb12u2
  • python-tornado Debian 14, Debian 13 6.4.2-2

debian advisories DEBIAN-CVE-2025-47287

  • python-tornado Ubuntu 24.04 LTS 6.4.0-1ubuntu0.2
  • python-tornado Ubuntu 25.10 6.4.2-2
  • python-tornado Ubuntu Pro 22.04 LTS 6.1.0-3ubuntu0.1~esm2

ubuntu advisories UBUNTU-CVE-2025-47287

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • pcs RHEL 8 0.10.18-2.el8_10.5
  • pcs-snmp RHEL 8 0.10.18-2.el8_10.5
  • python-tornado RHEL 9 6.4.2-2.el9_6.2
  • python3-tornado RHEL 9 6.4.2-2.el9_6.2
  • python-tornado RHEL 10.0 6.4.2-1.el10_0.1
  • python3-tornado RHEL 10.0 6.4.2-1.el10_0.1
  • python-tornado RHEL 7 ELS 4.2.1-5.el7_9.1
  • pcs RHEL 8.4 TUS, RHEL 8.4 E4S, RHEL 8.4 AUS 0.10.8-1.el8_4.7

red hat advisories RHSA-2025:8664RHSA-2025:8323RHSA-2025:8290RHSA-2025:8291RHSA-2025:8279RHSA-2025:8254

  • salt SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE Micro 5.2 +3 more 3006.0-150300.53.94.1
  • salt Linux Micro 6.1 3006.0-slfo.1.1_4.1
  • salt Linux Micro 6.0 3006.0-13.1
  • salt SLE Module for Systems Management 15 SP7 3006.0-150700.14.5.2
  • salt SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Module for Transactional Server 15 SP6 +6 more 3006.0-150500.4.55.1
  • salt-test openSUSE Leap 15.6 3006.0-150500.4.55.1
  • salt SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +5 more 3006.0-150400.8.80.1
  • venv-salt-minion Manager Client Tools for RHEL, Liberty and Clones 9-CLIENT-TOOLS, EL-9:Update:Products:SaltBundle:Update 3006.0-1.59.1

suse advisories SUSE-SU-2025:02534-1SUSE-SU-2025:20487-1SUSE-SU-2025:20504-1SUSE-SU-2025:02502-1SUSE-SU-2025:02501-1SUSE-SU-2025:02500-1

  • salt openSUSE Tumbleweed 3006.0-41.1
  • python-tornado6 openSUSE Tumbleweed 6.5-1.1

opensuse advisories openSUSE-SU-2025:15295-1openSUSE-SU-2025:15153-1

  • pcs AlmaLinux 8 0.10.18-2.el8_10.5.alma.1
  • pcs-snmp AlmaLinux 8 0.10.18-2.el8_10.5.alma.1
  • python3-tornado AlmaLinux 10 6.4.2-1.el10_0.1
  • python3-tornado AlmaLinux 9 6.4.2-2.el9_6.2

almalinux advisories ALSA-2025:8254ALSA-2025:8135ALSA-2025:8136

  • python-tornado Rocky Linux 9 6.4.2-2.el9_6.2
  • python-tornado Rocky Linux 10 6.4.2-1.el10_0.1
  • pcs Rocky Linux 8 0.10.18-2.el8_10.5

rocky linux advisories RLSA-2025:8136RLSA-2025:8135RLSA-2025:8254

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-2025-47287 updated cvss 7.5

tornado: Tornado Multipart Form-Data Denial of Service

  • Red Hat Enterprise Linux 9 pcs, pcs-snmp
    affected: workaround, no fix available “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.”
  • Red Hat Enterprise Linux AppStream (v. 9) python-tornado 6.4.2-2.el9_6.2, python3-tornado 6.4.2-2.el9_6.2
    fixed: vendor fix “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.” RHSA-2025:8136
  • Red Hat Enterprise Linux AppStream (v. 10) python-tornado 6.4.2-1.el10_0.1, python3-tornado 6.4.2-1.el10_0.1
    fixed: vendor fix “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.” RHSA-2025:8135
  • Red Hat Enterprise Linux AppStream EUS (v.9.2) python-tornado 6.4.2-1.el9_2.1, python3-tornado 6.4.2-1.el9_2.1
    fixed: vendor fix “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.” RHSA-2025:8226
  • Red Hat Enterprise Linux AppStream EUS (v.9.4) python-tornado 6.4.2-1.el9_4.1, python3-tornado 6.4.2-1.el9_4.1
    fixed: vendor fix “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.” RHSA-2025:8223
  • Red Hat Enterprise Linux High Availability AUS (v.8.4) pcs 0.10.8-1.el8_4.7, pcs-snmp 0.10.8-1.el8_4.7
    fixed: vendor fix “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.” RHSA-2025:8323
  • Red Hat Enterprise Linux High Availability E4S (v.8.6) pcs 0.10.12-6.el8_6.8, pcs-snmp 0.10.12-6.el8_6.8
    fixed: vendor fix “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.” RHSA-2025:8290
  • Red Hat Enterprise Linux High Availability E4S (v.9.0) pcs 0.11.1-10.el9_0.8, pcs-snmp 0.11.1-10.el9_0.8
    fixed: vendor fix “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.” RHSA-2025:8291
show 9 more
  • Red Hat Enterprise Linux High Availability EUS (v.8.8) pcs 0.10.15-4.el8_8.6, pcs-snmp 0.10.15-4.el8_8.6
    fixed: vendor fix “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.” RHSA-2025:8279
  • Red Hat Enterprise Linux High Availability TUS (v.8.6) pcs 0.10.12-6.el8_6.8, pcs-snmp 0.10.12-6.el8_6.8
    fixed: vendor fix “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.” RHSA-2025:8290
  • Red Hat Enterprise Linux HighAvailability (v. 8) pcs 0.10.18-2.el8_10.5, pcs-snmp 0.10.18-2.el8_10.5
    fixed: vendor fix “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.” RHSA-2025:8254
  • Red Hat Enterprise Linux HighAvailability E4S (v.8.4) pcs 0.10.8-1.el8_4.7, pcs-snmp 0.10.8-1.el8_4.7 Red Hat Enterprise Linux HighAvailability TUS (v.8.4) pcs 0.10.8-1.el8_4.7, pcs-snmp 0.10.8-1.el8_4.7
    fixed: vendor fix “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.” RHSA-2025:8323
  • Red Hat Enterprise Linux Resilient Storage EUS (v.8.8) pcs 0.10.15-4.el8_8.6, pcs-snmp 0.10.15-4.el8_8.6
    fixed: vendor fix “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.” RHSA-2025:8279
  • Red Hat Enterprise Linux ResilientStorage (v. 8) pcs 0.10.18-2.el8_10.5, pcs-snmp 0.10.18-2.el8_10.5
    fixed: vendor fix “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.” RHSA-2025:8254
  • Red Hat Enterprise Linux ResilientStorage E4S (v.9.0) pcs 0.11.1-10.el9_0.8, pcs-snmp 0.11.1-10.el9_0.8
    fixed: vendor fix “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.” RHSA-2025:8291
  • Red Hat Enterprise Linux Server Optional (v. 7 ELS) python-tornado 4.2.1-5.el7_9.1
    fixed: vendor fix “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.” RHSA-2025:8664
  • Red Hat OpenShift Container Platform 4 python-pep517, python-tornado, openshift4/ose-ovn-kubernetes, ose-ovn-kubernetes-base-container, openshift4/ose-ovn-kubernetes-rhel9, openshift4/ose-ovn-kubernetes-microshift-rhel9
    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

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
17 mo ago

Exploit prediction

0.74% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 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 7.5 CVSS:3.1/AV:N/AC:L/PR:N/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 tornado
<6.5
6.5

Affected products

  • tornadoweb tornado

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling

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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.