CVE-2026-116578

LOW
INFO Priority: 0.01 BB Relevance: 54/100
Published: 2026-10-26 Modified: 2026-10-26 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: Active
AT: Present
VC: None
VI: None
VA: None

Description

Tornado is a Python web framework and asynchronous networking library. Prior to 6.6, tornado.web.RedirectHandler URL templates can place regex-capture substitutions where crafted request paths change the redirect scheme or network location. Affected placements include substitutions at the start of a path, directly after a fixed host, or at the beginning of the template, including protocol-relative, absolute, backslash, encoded, host-extension, and user-info variants interpreted by browsers as attacker-controlled destinations. Static templates and substitutions after a fixed host followed by a slash are not affected. An attacker can use the resulting open redirect on the application's domain for phishing. This issue is fixed in version 6.6.

Weakness Classification (1)

Bug Bounty Relevance

54 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity

CVSS Score

2.1 / 10.0 v4.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N

EPSS — Exploitation Probability

0.46%
Raw Score 0.004590
Percentile 39.7%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00459
2026-10-28
0.00459

Intelligence Sources

mitre ref →
nvd ref →