CVE-2026-49854
Publication date 14 July 2026
Last updated 16 July 2026
Ubuntu priority
Description
Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, the optional native extension tornado.speedups implemented websocket_mask without validating that the mask argument is exactly four bytes, allowing the C function to read up to three bytes beyond the provided buffer when reached through Tornado XSRF token decoding with the native extension active. This issue is fixed in version 6.5.6.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| python-tornado | 26.04 LTS resolute |
Needs evaluation
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
|
| 16.04 LTS xenial |
Needs evaluation
|
Severity score breakdown
CVSS version: CVSS v3.0
Base score
5.3 · Medium
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
References
Other references
- https://www.cve.org/CVERecord?id=CVE-2026-49854
- https://github.com/tornadoweb/tornado/commit/96dc88c2a05705287856b2cd6b4b4034f9a6aaac
- https://github.com/tornadoweb/tornado/pull/3626
- https://github.com/tornadoweb/tornado/releases/tag/v6.5.6
- https://github.com/tornadoweb/tornado/security/advisories/GHSA-cx3h-4qpv-8hc9