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VulnerabilityPublished Updated

CVE-2025-47287: Python tornado · When Tornado's multipart/form-data parser encounters certain errors, it logs a

Affects python-tornadoSource GCVE Database

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Not known to be exploited · CVSS 7.5 High · fixed in 6.1.0-3ubuntu0.1~esm2 : patch python-tornado soon.

Data as of 6 Nov 2026, 23:24 UTC

CVSS 3.1 base score
7.5High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.7% chance of exploitation in 30 days – higher than 54% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 6.1.0-3ubuntu0.1~esm2, 6.4.0-1ubuntu0.2, 6.4.2-2
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 15 May 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.

What to do

Upgrade the Ubuntu python-tornado to 6.1.0-3ubuntu0.1~esm2 (package) or 6.4.0-1ubuntu0.2 (package) or 6.4.2-2 (package).

Affected software

ProductAffectedFixed in
Ubuntu 25.10python-tornadopkg:deb/ubuntu/python-tornado?arch=source&distro=questingOther threatsAffected
  • <6.4.2-2
Fixed in
  • 6.4.2-2
Ubuntu 24.04 LTSpython-tornadopkg:deb/ubuntu/python-tornado?arch=source&distro=nobleOther threatsAffected
  • <6.4.0-1ubuntu0.2
Fixed in
  • 6.4.0-1ubuntu0.2
Ubuntu Pro 22.04 LTSpython-tornadopkg:deb/ubuntu/python-tornado?arch=source&distro=esm-apps/jammyOther threatsAffected
  • <6.1.0-3ubuntu0.1~esm2
Fixed in
  • 6.1.0-3ubuntu0.1~esm2
Ubuntu Pro 20.04 LTSpython-tornadopkg:deb/ubuntu/python-tornado?arch=source&distro=esm-apps/focalOther threatsAffected
  • 5.1.1-4ubuntu1 – 6.0.3+really5.1.1-3ubuntu0.1~esm8
11 affected builds
Fixed in–
Ubuntu Pro 18.04 LTSpython-tornadopkg:deb/ubuntu/python-tornado?arch=source&distro=esm-apps/bionicOther threatsAffected
  • 4.5.1-2.1~build2 – 4.5.3-1ubuntu0.2+esm5
10 affected builds
Fixed in–
Ubuntu Pro 16.04 LTSpython-tornadopkg:deb/ubuntu/python-tornado?arch=source&distro=esm-infra-legacy/xenialOther threatsAffected
  • 4.2.1-1ubuntu2 – 4.2.1-1ubuntu3.1+esm5
8 affected builds
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available and should be applied by upgrading Tornado to version 6.5.0 or later. Ubuntu users should update to the fixed package versions: 6.1.0-3ubuntu0.1~esm2, 6.4.0-1ubuntu0.2, or 6.4.2-2 as appropriate. As a temporary workaround, blocking HTTP requests with the Content-Type header set to multipart/form-data at a proxy can reduce exposure to this vulnerability.

Description

Tornado, a Python web framework, has a vulnerability in its multipart/form-data parser that causes excessive logging when encountering certain errors. This can be exploited by remote attackers to generate a high volume of logs, leading to a denial of service (DoS) due to synchronous logging. All Tornado versions prior to 6.5.0 are affected. The issue is patched in Tornado version 6.5.0 and later. As a workaround, blocking multipart/form-data content types at a proxy can mitigate the risk.

References

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