What is CVE-2026-49854?

CVE-2026-49854 is a medium-severity vulnerability in Tornadoweb Tornado, classified under Buffer Over-read. CVSS score: 5.3/10. Published 2026-07-14.

How severe is CVE-2026-49854?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Tornadoweb Tornado

CVE-2026-49854

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…

CVSS v3 metric

CVSS v3 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.

Affected products

Tornadoweb Tornado — versions < 6.5.6

Weakness classification (CWE)

CWE-126 — Buffer Over-read

References

security-advisories@github.com (x_refsource_CONFIRM)
security-advisories@github.com (x_refsource_MISC)
security-advisories@github.com (x_refsource_MISC)
security-advisories@github.com (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-49854?: CVE-2026-49854 is a medium-severity vulnerability in Tornadoweb Tornado, classified under Buffer Over-read. CVSS score: 5.3/10. Published 2026-07-14.
How severe is CVE-2026-49854?: Medium severity. CVSS v3 base score is 5.3 out of 10.