CVE-2026-27205
Flask session does not add `Vary: Cookie` header when accessed in some ways
描述
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 Information vulnerability. The logic instructs caches not to cache the response, as it may contain information specific to a logged in user. This is handled in most cases, but some forms of access such as the Python in operator were overlooked. The severity and risk depend on the application being hosted behind a caching proxy that doesn't ignore responses with cookies, not setting a Cache-Control header to mark pages as private or non-cacheable, and accessing the session in a way that only touches keys without reading values or mutating the session. The issue has been fixed in version 3.1.3.
如何修補 CVE-2026-27205
要修補 CVE-2026-27205,請將受影響套件升級到下列已修補版本。
- —升級至 3.1.3 或更新版本
- —升級至 3.1.3 或更新版本
CVE-2026-27205 正在被利用嗎?
低 — EPSS 為 0.4%,目前沒有觀察到大規模利用活動。
受影響套件(2)
- from 0, < 3.1.3
- from 0, < 3.1.3
CVSS 分數
| 來源 | 版本 | 嚴重程度 | 向量 |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N |
| osv | CVSS 3.1 | MEDIUM4.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N |