tocsin

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