Vulnerability in Pallets Flask

CVE-2026-27205

Flask is a web server gateway interface (WSGI) web application framework. In versions 3.1.2 and below, when the session object is accessed, Flask should set the Vary: Cookie header., resulting in a Use of Cache Containing Sensitive Informa…

EPSS: 0.000 (2.7th percentile) — read the EPSS interpretation.

Affected products

Weakness classification (CWE)

References