CVE-2026-31958
Publication date 11 March 2026
Last updated 23 April 2026
Ubuntu priority
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| python-tornado | 26.04 LTS resolute |
Vulnerable
|
| 25.10 questing |
Fixed 6.4.2-3ubuntu0.3
|
|
| 24.04 LTS noble |
Fixed 6.4.0-1ubuntu0.5
|
|
| 22.04 LTS jammy |
Fixed 6.1.0-3ubuntu0.1~esm5
|
|
| 20.04 LTS focal |
Fixed 6.0.3+really5.1.1-3ubuntu0.1~esm5
|
|
| 18.04 LTS bionic |
Fixed 4.5.3-1ubuntu0.2+esm3
|
|
| 16.04 LTS xenial |
Fixed 4.2.1-1ubuntu3.1+esm3
|
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Related Ubuntu Security Notices (USN)
- USN-8198-1
- Tornado vulnerabilities
- 22 April 2026