CVE-2025-47287: Python tornado · When Tornado's multipart/form-data parser encounters certain errors, it logs a warning but continues trying to parse the remainder of the data
Affects python-tornadoSource GCVE Database
Not known to be exploited · CVSS 7.5 Medium : upgrade to 6.1.0-3ubuntu0.1~esm2 when convenient.
Data as of 25 Oct 2026, 19:02 UTC
- 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 2.2.2_2, 2.17_1, 6.1.0-3ubuntu0.1~esm2 +2
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 May 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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 2026-10-25.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewsnakevizpkg:brew/snakevizOther threats | Affected
| Fixed in
|
Homebrewnvcheckerpkg:brew/nvcheckerOther threats | Affected
| Fixed in
|
Ubuntu:Pro:16.04:LTSpython-tornadopkg:deb/ubuntu/python-tornado?arch=source&distro=esm-infra-legacy/xenialOther threats | Affected
| Fixed in– |
Ubuntu:Pro:18.04:LTSpython-tornadopkg:deb/ubuntu/python-tornado?arch=source&distro=esm-apps/bionicOther threats | Affected
| Fixed in– |
Ubuntu:Pro:20.04:LTSpython-tornadopkg:deb/ubuntu/python-tornado?arch=source&distro=esm-apps/focalOther threats | Affected
| Fixed in– |
Ubuntu:Pro:22.04:LTSpython-tornadopkg:deb/ubuntu/python-tornado?arch=source&distro=esm-apps/jammyOther threats | Affected
| Fixed in
|
Ubuntu:24.04:LTSpython-tornadopkg:deb/ubuntu/python-tornado?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu:25.10python-tornadopkg:deb/ubuntu/python-tornado?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Red Hat has released an updated python-tornado package version 6.4.2-1.el10_0.1 that addresses this vulnerability. Users should apply the update as described in Red Hat advisory RHSA-2025:8135 and the referenced article https://access.redhat.com/articles/11258 to remediate this issue. No other mitigation steps are indicated by the vendor.
Description
### Summary 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. ### Affected versions All versions of Tornado prior to 6.5 are affected. The vulnerable parser is enabled by default. ### Solution Upgrade to Tornado version 6.5. In the meantime, risk can be mitigated by blocking `Content-Type: multipart/form-data` in a proxy.
References
- access.redhat.com/errata/RHSA-2025:8135 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2366703 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2025/rhsa-2025_8135.json (opens in a new tab)
- github.com/tornadoweb/tornado/security/advisories/GHSA-7cx3-6m66-7c5m (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2025-47287 (opens in a new tab)
- github.com/tornadoweb/tornado/commit/b39b892bf78fe8fea01dd45199aa88307e7162f3 (opens in a new tab)
- github.com/tornadoweb/tornado (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/05/msg00038.html (opens in a new tab)
- suse.com/support/security/rating/ (opens in a new tab)
- ftp.suse.com/pub/projects/security/csaf/rhsa-2025_8136.json (opens in a new tab)
- lists.suse.com/pipermail/suse-liberty-linux-updates/2025-June/001547.html (opens in a new tab)
- suse.com/security/cve/CVE-2025-47287/ (opens in a new tab)
- ubuntu.com/security/CVE-2025-47287 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-47287 (opens in a new tab)
- ubuntu.com/security/notices/USN-7547-1 (opens in a new tab)