CVE-2026-49854

MEDIUM
MEDIUM Priority: 0.02 BB Relevance: 71/100
Published: 2026-07-14 Modified: 2026-10-24 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: Unchanged
C: Low
I: None
A: None

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.

Weakness Classification (1)

Bug Bounty Relevance

71 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

5.3 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS — Exploitation Probability

0.42%
Raw Score 0.004190
Percentile 36.2%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00419
2026-10-28
0.00419

Intelligence Sources

nvd ref →