tocsin

CVE-2026-27205

2 advisories.

PyPI/flask CVE-2026-27205: low, EPSS 0.48%

Flask session does not add `Vary: Cookie` header when accessed in some ways

Action: Upgrade flask to 3.1.3 or later.

pip install flask==3.1.3

Affected

introducedfixedlast affected
03.1.3-

Fixed versions

3.1.3

Sources

CVE-2026-27205 · published · modified · JSON

PyPI/flask CVE-2026-27205: medium 4.3, EPSS 0.48%

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 Us

Action: Upgrade flask to 3.1.3 or later.

pip install flask==3.1.3

Affected

introducedfixedlast affected
03.1.3-

Fixed versions

3.1.3

Sources

CVE-2026-27205 · published · modified · JSON