Back to CVE records
High 7.5Published Mar 11, 2026

CVE-2026-31958Tornado is a Python web framework and asynchronous networking library.

Updated under an hour ago ()

Does this affect you?

It affects tornadoweb tornado. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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.

CVSS
7.5 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE)
CWE-400
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
Not given
NVD analysis
Modified
Record last updated
Jun 17, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
tornadoweb tornado
tornadoweb:tornado
before 6.5.5
NVD

References

  • vendor-advisory

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

Your cookie choices
We use essential cookies to run this site, and, only with your consent, an advertising cookie from Google to measure whether our ads lead to sign-ups and subscriptions. See our for details.