CVE-2026-31958: tornadoweb tornado · Uncontrolled Resource Consumption
Affects tornadoweb tornadoSource CVE Database V5
Not known to be exploited · CVSS 8.7 High : upgrade to 6.5.5 soon.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 33% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.5.5
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 11 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 24 Oct 2026.
What to do
Upgrade tornadoweb tornado to 6.5.5.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| tornadowebtornado | Affected
| Fixed in
|
PyPItornadopkg:pypi/tornadoOther 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
Upgrade Tornado to version 6.5.5 or later, where this vulnerability is fixed. Since the vendor advisory confirms the fix in 6.5.5, applying this official patch is the recommended remediation. No other mitigations are indicated.
Description
Tornado is a Python web framework and asynchronous networking library. 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_size setting (default 100MB). Since parsing occurs synchronously on the main thread, this creates the possibility of denial-of-service due to the cost of parsing very large multipart bodies with many parts. This vulnerability is fixed in 6.5.5.