CVE-2019-1010083: Flask - Unexpected Memory Usage Denial of Service
Summary
CVE-2019-1010083: The Pallets Project Flask before 1.0 is affected by: unexpected memory usage. Affects flask versions < 1.0. Fixed in 1.0. How to fix ↓
Also tracked for
- flask · Debian:11
The same CVE-2019-1010083 is tracked separately for each ecosystem and vendor. Its fix information is the same; the package and affected versions differ.
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Background
Flask is a popular Python web framework used for developing web applications. It provides a simple and flexible way to build web applications. Flask is vulnerable to unexpected memory usage, which can lead to a denial of service (DoS) attack. This vulnerability affects Flask versions before 1.0.
Vulnerability Detail
The vulnerability in Flask is triggered by crafted encoded JSON data. An attacker can exploit this vulnerability to cause unexpected memory usage, resulting in a DoS condition. The impact of this vulnerability is a potential disruption of the Flask application, rendering it unavailable to legitimate users. It is important to note that this vulnerability may overlap with CVE-2018-1000656.
How To Fix
Latest published version: 3.1.3 as of 22 Oct 2026
pip install --upgrade "flask==3.1.3"Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
1.0
This is the first release that contains the fix.
pip install --upgrade "flask==1.0"Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Conclusion
Flask versions before 1.0 are vulnerable to unexpected memory usage, which can result in a denial of service (DoS) condition. To mitigate this risk, it is crucial to update Flask to version 1.0 or later. For further assistance on vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for flask →
FAQ
The impact of this vulnerability is a potential denial of service (DoS) condition, which can render the Flask application unavailable to legitimate users.
An attacker can exploit this vulnerability by sending crafted encoded JSON data to the Flask application, causing unexpected memory usage and potentially leading to a DoS attack.
Flask versions before 1.0 are affected by this vulnerability.
Yes, updating Flask to version 1.0 or later will fix this vulnerability.
No, there are no known workarounds for this vulnerability. It is recommended to update Flask to the fixed version.
References
Related vulnerabilities
Recent vulnerabilities recorded for flask.
