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Tornado CVE-2025-47287

HIGH
Allocation of Resources Without Limits or Throttling (CWE-770)
2025-05-15 security-advisories@github.com
7.5
CVSS 3.1 · GitHub Advisory
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Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A06:2025 - Insecure Design
ASVS 5.0
V2 - Validation and Business Logic Resource allocation limits
MITRE ATT&CK

1 technique across 1 tactic: Impact

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Impact

CVSS score of 7.5 (HIGH). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. EPSS exploitation probability: 1.16%.

Exploit ScenarioDerived

A remote attacker could exhaust system resources through uncontrolled allocation by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability.

This Month Plan within 30 days. Why: HIGH severity (CVSS 7.0-8.9).
Patch available 1.2% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 28, 2026

Tornado is a Python web framework and asynchronous networking library. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Allocation of Resources Without Limits vulnerability could allow attackers to exhaust system resources through uncontrolled allocation.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Set resource limits, implement rate limiting, validate input sizes.

Affected Packages

pypi tornado fix: 6.5

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in pypi

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as Allocation of Resources Without Limits (CWE-770), which allows attackers to exhaust system resources through uncontrolled allocation. 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. Affected products include: Tornadoweb Tornado, Debian Debian Linux. Version information: prior to 6.5.0.

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

GitHub Advisory PRIMARY 7.5 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SUSE HIGH
Red Hat 7.5 HIGH

Primary rating from GitHub Advisory.

CVSS VectorGitHub Advisory

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Lifecycle Timeline

2
Patch released
Mar 28, 2026 - 18:42 nvd
Patch available
CVE Published
May 15, 2025 - 22:15 nvd
HIGH 7.5

DescriptionGitHub Advisory

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.

Blast Radius

ecosystem impact
† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth
  • 10 pypi packages depend on tornado (9 direct, 1 indirect)

Ecosystem-wide dependent count for version 6.5.

Executive ViewAI

Why It Matters

Organizations using Tornado face notable risk from CVE-2025-47287 rated CVSS 7.5. Exploitation could compromise the security of affected deployments. A patch is available and should be applied as part of regular vulnerability management.

Business Impact: High
Compensating Controls

Apply vendor patch. If immediate patching is not feasible: (1) Implement network-level access controls to limit exposure; (2) Enable enhanced monitoring and alerting; (3) Apply principle of least privilege.

Threat Intelligence Overview

EPSS Score
1.2%
Top 21% exploitable

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 1.2%
Patch available Yes
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
Yes
Human Impact
High

Priority Score

39
Low Medium High Critical
KEV: 0
EPSS: +1
CVSS: +38
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.

Affected Products (CPE)GitHub Advisory

cpe:2.3:a:tornadoweb:tornado:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
CVE-2024-42733 CRITICAL POC
9.8 Mar 07

An issue in Docmosis Tornado v.2.9.7 and before allows a remote attacker to execute arbitrary code via a crafted script

CVE-2023-25266 HIGH POC
8.8 Feb 28

An issue was discovered in Docmosis Tornado prior to version 2.9.5. Rated high severity (CVSS 8.8), this vulnerability i

CVE-2025-67726 HIGH POC
7.5

py3-tornado in Alpine Linux received a security fix packaged as version 6.5.4-r0, addressing an unspecified vulnerabilit

CVE-2023-25265 HIGH POC
7.5 Feb 28

Docmosis Tornado <= 2.9.4 is vulnerable to Directory Traversal leading to the disclosure of arbitrary content on the fil

CVE-2023-25264 HIGH POC
7.5 Feb 28

An issue was discovered in Docmosis Tornado prior to version 2.9.5. Rated high severity (CVSS 7.5), this vulnerability i

CVE-2026-103262 HIGH
8.7 Oct 01

Denial of service in the Tornado web framework's CurlAsyncHTTPClient (all releases before 6.5.9) lets an unauthenticated

CVE-2026-31958 HIGH
8.7 Mar 11

In versions of Tornado prior to 6.5.5, the only limit on the number of parts in `multipart/form-data` is the `max_body_s

CVE-2026-91990 HIGH
8.7 Sep 15

Memory amplification denial of service in the Tornado Python web framework before 6.5.8 lets unauthenticated remote atta

CVE-2026-91992 HIGH
8.2 Sep 15

Credential leakage in Tornado's CurlAsyncHTTPClient (all releases through 6.5.6) lets sensitive per-request state — clie

CVE-2026-103263 HIGH
8.2 Oct 01

Unauthenticated local file disclosure in Tornado before 6.5.9 lets remote attackers read files outside a configured stat

CVE-2026-82397 HIGH
7.5 Aug 31

Denial-of-service in Tornado prior to 6.5.8 allows unauthenticated remote attackers to stall the entire server by sendin

CVE-2025-67725 HIGH
7.5

Tornado Python web framework on Alpine Linux received a security fix in package version 6.5.4-r0, addressing an uncharac

Vendor StatusVendor

SUSE

Severity: High
Product Status
Container suse/manager/5.0/x86_64/proxy-httpd:5.0.5.7.23.1 Affected
Container suse/manager/5.0/x86_64/server:5.0.5.7.30.1 Affected
Container suse/sl-micro/6.0/baremetal-os-container:latest Container suse/sl-micro/6.0/base-os-container:latest Container suse/sl-micro/6.0/kvm-os-container:latest Container suse/sl-micro/6.0/rt-os-container:latest Container suse/sl-micro/6.0/toolbox:latest Affected
Image SLES15-SP3-Micro-5-2-BYOS-Azure Image SLES15-SP3-Micro-5-2-BYOS-EC2-HVM Image SLES15-SP3-Micro-5-2-BYOS-GCE Affected
Image SLES15-SP4-BYOS Image SLES15-SP4-BYOS-Azure Image SLES15-SP4-BYOS-EC2 Image SLES15-SP4-BYOS-GCE Image SLES15-SP4-HPC-BYOS Image SLES15-SP4-HPC-BYOS-Azure Image SLES15-SP4-HPC-BYOS-EC2 Image SLES15-SP4-HPC-BYOS-GCE Image SLES15-SP4-HPC-EC2 Image SLES15-SP4-HPC-GCE Image SLES15-SP4-Hardened-BYOS Image SLES15-SP4-Hardened-BYOS-Azure Image SLES15-SP4-Hardened-BYOS-EC2 Image SLES15-SP4-Hardened-BYOS-GCE Image SLES15-SP4-Manager-Proxy-4-3-BYOS Image SLES15-SP4-Manager-Proxy-4-3-BYOS-Azure Image SLES15-SP4-Manager-Proxy-4-3-BYOS-EC2 Image SLES15-SP4-Manager-Proxy-4-3-BYOS-GCE Affected

References

Advisories & patches
PATCH https://github.com/tornadoweb/tornado/commit/b39b892bf78fe8fea01dd45199aa88307e7162f3 ADVISORY https://access.redhat.com/errata/RHSA-2025:8135 ADVISORY https://access.redhat.com/errata/RHSA-2025:8136 ADVISORY https://access.redhat.com/errata/RHSA-2025:8223 ADVISORY https://access.redhat.com/errata/RHSA-2025:8226 ADVISORY https://access.redhat.com/errata/RHSA-2025:8254 ADVISORY https://access.redhat.com/errata/RHSA-2025:8279 ADVISORY https://access.redhat.com/errata/RHSA-2025:8290 ADVISORY https://access.redhat.com/errata/RHSA-2025:8291 ADVISORY https://access.redhat.com/errata/RHSA-2025:8323 ADVISORY https://access.redhat.com/errata/RHSA-2025:8664 ADVISORY https://github.com/tornadoweb/tornado/security/advisories/GHSA-7cx3-6m66-7c5m ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:01649/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:01726/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:01732/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:02478/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:02491/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:02492/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:02496/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:02499/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:02500/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:02501/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:02502/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:02534/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:02576/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:02577/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:02578/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:15153/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:20430/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:20445/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:20487/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:20504/ ADVISORY https://www.suse.com/support/update/SUSE-SU-2025:20505/ REF https://lists.debian.org/debian-lts-announce/2025/05/msg00038.html

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