cve.bz

CVE-2021-33026

9.8 criticalEPSS 7.3%

Critical (9.8) in flask-caching project flask-caching. EPSS 7.3% chance of exploitation in the next 30 days.

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

Severity

CVSS 3.1

9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
7.3% chance of exploitation in the next 30 days; higher than 94% of CVEs (scores of 2026-10-31)
CWE
CWE-502
Published
Modified
Record from
the NVD, synced

Affected

Packages (OSV)

AdvisoryEcosystemPackageAffectedFixed in
GHSA-656c-6cxf-hvcvPyPIflask-caching<=1.10.1no fix published

References

Check your stackJSON