CVE-2018-1000656
python-flask: Denial of Service via crafted JSON file
Severity
LowRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · April 10, 2018
Updated · November 21, 2025
Description
The Pallets Project flask version Before 0.12.3 contains a CWE-20: Improper Input Validation vulnerability in flask that can result in Large amount of memory usage possibly leading to denial of service. This attack appear to be exploitable via Attacker provides JSON data in incorrect encoding. This vulnerability appears to have been fixed in 0.12.3. NOTE: this may overlap CVE-2019-1010083.
Statement
This issue affects the versions of python-flask as shipped with Red Hat Enterprise Linux 7.
Although Red Hat Satellite 6 contains the vulnerable component, the former is not affected due to python-flask only receiving JSON data created by other Red Hat Satellite 6 components, not user-controlled JSON data, which makes the attack unfeasible.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE-20 · Improper Input Validation