CVE-2026-91991EPSS p14.5%

CVE-2026-91991CVE-2026-91991

Description

Tornado before 6.5.8 contains an incomplete fix for cookie attribute injection that allows attackers to inject arbitrary cookie attributes by passing capitalized or legacy keyword arguments to set_cookie. Attackers can embed semicolon-delimited data in capitalized parameters like Domain, Path, or SameSite to bypass validation and modify cookie security attributes.

Scoring

CVSS 5.4 ()
VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
EPSS0.25% probability of exploitation · percentile 14.5% · 2026-10-05T12:00:23Z
Last modified2026-09-21
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.