CVE-2026-49854

EUVD-2026-44504
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
GitHub_MCNA
5.3 MEDIUM
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 26.24%
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
tornadowebtornado
𝑥
< 6.5.6
CNA
Debian logo
Debian Releases
Debian Product
Codename
python-tornado
bookworm
vulnerable
bookworm (security)
vulnerable
bullseye
vulnerable
bullseye (security)
vulnerable
forky
vulnerable
sid
vulnerable
trixie
no-dsa
trixie (security)
vulnerable
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
python-tornado
bionic
needs-triage
focal
needs-triage
jammy
needs-triage
noble
needs-triage
resolute
needs-triage
xenial
needs-triage
openSUSE logo
openSUSE / SLES Releases
openSUSE Product
Release
python3-tornado
suse enterprise sap 15 SP4
4.5.3-150000.3.22.1
fixed
suse enterprise sap 15 SP5
4.5.3-150000.3.22.1
fixed
suse enterprise sap 15 SP6
4.5.3-150000.3.22.1
fixed
suse enterprise server 15 SP4
4.5.3-150000.3.22.1
fixed
suse enterprise server 15 SP5
4.5.3-150000.3.22.1
fixed
suse enterprise server 15 SP6
4.5.3-150000.3.22.1
fixed
python311-tornado6
suse enterprise desktop 15 SP7
6.3.2-150400.9.18.1
fixed
suse enterprise sap 15 SP4
6.3.2-150400.9.18.1
fixed
suse enterprise sap 15 SP5
6.3.2-150400.9.18.1
fixed
suse enterprise sap 15 SP6
6.3.2-150400.9.18.1
fixed
suse enterprise sap 15 SP7
6.3.2-150400.9.18.1
fixed
suse enterprise server 15 SP4
6.3.2-150400.9.18.1
fixed
suse enterprise server 15 SP5
6.3.2-150400.9.18.1
fixed
suse enterprise server 15 SP6
6.3.2-150400.9.18.1
fixed
suse enterprise server 15 SP7
6.3.2-150400.9.18.1
fixed
Amazon Linux logo
Amazon Linux Releases
Amazon Package
Release
python-tornado
Amazon Linux 2
0:4.2.1-3.amzn2.0.6
fixed
python-tornado-debuginfo
Amazon Linux 2
0:4.2.1-3.amzn2.0.6
fixed
python-tornado-debugsource
Amazon Linux 2023
0:6.1.0-2.amzn2023.0.9
fixed
python-tornado-doc
Amazon Linux 2
0:4.2.1-3.amzn2.0.6
fixed
Amazon Linux 2023
0:6.1.0-2.amzn2023.0.9
fixed
python3-tornado
Amazon Linux 2
0:5.0.2-4.amzn2.0.9
fixed
Amazon Linux 2023
0:6.1.0-2.amzn2023.0.9
fixed
python3-tornado-debuginfo
Amazon Linux 2
0:5.0.2-4.amzn2.0.9
fixed
Amazon Linux 2023
0:6.1.0-2.amzn2023.0.9
fixed
python3-tornado-doc
Amazon Linux 2
0:5.0.2-4.amzn2.0.9
fixed
python3.13-tornado
Amazon Linux 2023
0:6.4.2-1.amzn2023.0.4
fixed
python3.13-tornado-debuginfo
Amazon Linux 2023
0:6.4.2-1.amzn2023.0.4
fixed
python3.13-tornado-debugsource
Amazon Linux 2023
0:6.4.2-1.amzn2023.0.4
fixed
python3.13-tornado-doc
Amazon Linux 2023
0:6.4.2-1.amzn2023.0.4
fixed
Common Weakness Enumeration
References
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