VULNERABILITY INTELLIGENCE
CVE-2021-33026
CVSS score9.8 CRITICAL
EPSS probability7.35%
CISA KEVNot currently listed
Published2021-05-13
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Description
The Flask-Caching extension through 1.10.1 for Flask relies on Pickle for serialization, which may lead to remote code execution or local privilege escalation. If an attacker gains access to cache storage (e.g., filesystem, Memcached, Redis, etc.), they can construct a crafted payload, poison the cache, and execute Python code. NOTE: a third party indicates that exploitation is extremely unlikely unless the machine is already compromised; in other cases, the attacker would be unable to write their payload to the cache and generate the required collision
Weakness classification
- nvd@nist.gov: CWE-502
- 134c704f-9b21-4f2e-91b3-4a467353bcc0: CWE-502
Primary references
- cve@mitre.org — Issue Tracking, Patch, Third Party Advisory
- cve@mitre.org — Patch, Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Issue Tracking, Patch, Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Patch, Third Party Advisory