Deserialization in Bentoml

CVE-2025-27520

BentoML is a Python library for building online serving systems optimized for AI apps and model inference. A Remote Code Execution (RCE) vulnerability caused by insecure deserialization has been identified in the latest version (v1.4.2) of BentoML. It allows any unauthenticated user to execute arbitrary code on the server. It exists an unsafe code segment in serde.py. This vulnerability is fixed in 1.4.3.

Vulnerability class: Insecure Deserialization

EPSS: 0.357 (98.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

  • Bentoml — versions >= 1.3.4, < 1.4.3

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-27520?
CVE-2025-27520 is a critical-severity vulnerability in Bentoml, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2025-04-04.
How severe is CVE-2025-27520?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2025-27520 known to be exploited?
7 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.