Upstream information
Description
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.SUSE information
Overall state of this security issue: Pending
This issue is currently rated as having moderate severity.
| CVSS detail | National Vulnerability Database | SUSE |
|---|---|---|
| Base Score | 4.3 | 6.5 |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
| Attack Vector | Network | Network |
| Attack Complexity | Low | Low |
| Privileges Required | None | None |
| User Interaction | Required | Required |
| Scope | Unchanged | Unchanged |
| Confidentiality Impact | Low | High |
| Integrity Impact | None | None |
| Availability Impact | None | None |
| CVSSv3 Version | 3.1 | 3.1 |
| CVSS detail | CNA (GitHub) | SUSE |
|---|---|---|
| Base Score | 2.3 | 6 |
| Vector | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N |
| Attack Vector | Network | Network |
| Attack Complexity | Low | Low |
| Attack Requirements | Present | Present |
| Privileges Required | None | None |
| User Interaction | Passive | Passive |
| Vulnerable System Confidentiality Impact | Low | High |
| Vulnerable System Integrity Impact | None | None |
| Vulnerable System Availability Impact | None | None |
| Subsequent System Confidentiality Impact | None | None |
| Subsequent System Integrity Impact | None | None |
| Subsequent System Availability Impact | None | None |
| CVSSv4 Version | 4.0 | 4.0 |
Status of this issue by product and package
Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.
| Product(s) | Source package | State |
|---|---|---|
| Products under general support and receiving all security fixes. | ||
| SUSE Linux Enterprise Desktop 15 SP7 | python-Flask | Affected |
| SUSE Linux Enterprise High Performance Computing 12 | python-Flask | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP7 | python-Flask | Affected |
| SUSE Linux Enterprise Module for Python 3 15 SP7 | python-Flask | Affected |
| SUSE Linux Enterprise Server 15 SP7 | python-Flask | Affected |
| SUSE Linux Enterprise Server 16.0 | python-Flask | Affected |
| SUSE Linux Enterprise Server 16.1 | python-Flask | Ignore |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | python-Flask | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.0 | python-Flask | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | python-Flask | Ignore |
| openSUSE Leap 15.6 | python-Flask | Affected |
| Products under Long Term Service Pack support and receiving important and critical security fixes. | ||
| SUSE Linux Enterprise High Performance Computing 15 SP4 | python-Flask | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | python-Flask | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | python-Flask | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | python-Flask | Affected |
| SUSE Linux Enterprise Module for Public Cloud 12 | python-Flask | Affected |
| SUSE Linux Enterprise Module for Python 3 15 SP4 | python-Flask | Affected |
| SUSE Linux Enterprise Module for Python 3 15 SP5 | python-Flask | Affected |
| SUSE Linux Enterprise Server 12 SP5 | python-Flask | Affected |
| SUSE Linux Enterprise Server 15 SP4 | python-Flask | Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | python-Flask | Affected |
| SUSE Linux Enterprise Server 15 SP5 | python-Flask | Affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | python-Flask | Affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | python-Flask | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP5 | python-Flask | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | python-Flask | Affected |
| SUSE Manager Proxy 4.3 | python-Flask | Affected |
| SUSE Manager Retail Branch Server 4.3 | python-Flask | Affected |
| SUSE Manager Server 4.3 | python-Flask | Affected |
| Products past their end of life and not receiving proactive updates anymore. | ||
| SUSE CaaS Platform 4.0 | python-Flask | Affected |
| SUSE Enterprise Storage 6 | python-Flask | Affected |
| SUSE Enterprise Storage 7 | python-Flask | Affected |
| SUSE Enterprise Storage 7.1 | python-Flask | Affected |
| SUSE Linux Enterprise Desktop 15 SP1 | python-Flask | Affected |
| SUSE Linux Enterprise Desktop 15 SP2 | python-Flask | Affected |
| SUSE Linux Enterprise Desktop 15 SP3 | python-Flask | Affected |
| SUSE Linux Enterprise Desktop 15 SP4 | python-Flask | Affected |
| SUSE Linux Enterprise Desktop 15 SP5 | python-Flask | Affected |
| SUSE Linux Enterprise Desktop 15 SP6 | python-Flask | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1 | python-Flask | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS | python-Flask | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS | python-Flask | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | python-Flask | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | python-Flask | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | python-Flask | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | python-Flask | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | python-Flask | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | python-Flask | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | python-Flask | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | python-Flask | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | python-Flask | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP1 | python-Flask | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP2 | python-Flask | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP3 | python-Flask | Affected |
| SUSE Linux Enterprise Module for Package Hub 15 SP1 | python-Flask | Affected |
| SUSE Linux Enterprise Module for Package Hub 15 SP2 | python-Flask | Affected |
| SUSE Linux Enterprise Module for Package Hub 15 SP3 | python-Flask | Affected |
| SUSE Linux Enterprise Module for Package Hub 15 SP4 | python-Flask | Affected |
| SUSE Linux Enterprise Module for Package Hub 15 SP5 | python-Flask | Affected |
| SUSE Linux Enterprise Module for Python 3 15 SP6 | python-Flask | Affected |
| SUSE Linux Enterprise Real Time 15 SP2 | python-Flask | Affected |
| SUSE Linux Enterprise Real Time 15 SP3 | python-Flask | Affected |
| SUSE Linux Enterprise Server 12 | python-Flask | Affected |
| SUSE Linux Enterprise Server 12 SP3 | python-Flask | Affected |
| SUSE Linux Enterprise Server 12 SP4 | python-Flask | Affected |
| SUSE Linux Enterprise Server 15 SP1 | python-Flask | Affected |
| SUSE Linux Enterprise Server 15 SP1-BCL | python-Flask | Affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | python-Flask | Affected |
| SUSE Linux Enterprise Server 15 SP2 | python-Flask | Affected |
| SUSE Linux Enterprise Server 15 SP2-BCL | python-Flask | Affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | python-Flask | Affected |
| SUSE Linux Enterprise Server 15 SP3 | python-Flask | Affected |
| SUSE Linux Enterprise Server 15 SP3-BCL | python-Flask | Affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | python-Flask | Affected |
| SUSE Linux Enterprise Server 15 SP6 | python-Flask | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 | python-Flask | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP3 | python-Flask | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP4 | python-Flask | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP1 | python-Flask | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | python-Flask | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | python-Flask | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | python-Flask | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | python-Flask | Affected |
| SUSE Manager Proxy 4.0 | python-Flask | Affected |
| SUSE Manager Proxy 4.1 | python-Flask | Affected |
| SUSE Manager Proxy 4.2 | python-Flask | Affected |
| SUSE Manager Retail Branch Server 4.0 | python-Flask | Affected |
| SUSE Manager Retail Branch Server 4.1 | python-Flask | Affected |
| SUSE Manager Retail Branch Server 4.2 | python-Flask | Affected |
| SUSE Manager Server 4.0 | python-Flask | Affected |
| SUSE Manager Server 4.1 | python-Flask | Affected |
| SUSE Manager Server 4.2 | python-Flask | Affected |
| openSUSE Leap 15.3 | python-Flask | Affected |
| openSUSE Leap 15.4 | python-Flask | Affected |
| openSUSE Leap 15.5 | python-Flask | Affected |
SUSE Timeline for this CVE
CVE page created: Sat Feb 21 08:00:12 2026CVE page last modified: Thu Feb 26 16:48:41 2026