Deserialization in N/a

CVE-2026-31072

The JSONSerializer and CBORSerializer in APScheduler (all versions including 3.10.x and 4.0.0a5) are vulnerable to Remote Code Execution (RCE) via Insecure Deserialization. The unmarshal_object function allows for arbitrary class instantiation and state injection by dynamically importing modules and calling __setstate__ on any class available in the Python environment. An attacker can exploit this by submitting a specially crafted JSON or CBOR payload to an application using these serializers

Vulnerability class: Insecure Deserialization

Published · last modified .

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.

EPSS exploit prediction

EPSS: 0.010 (61.7th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 62nd percentile — 61.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-31072: held from 0.008 to 0.010.

EPSS over last 30 days · oldest: 0.008 · newest: 0.010 · change: +0.002

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-31072?
CVE-2026-31072 is a critical-severity vulnerability in N/a, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2026-05-19.
How severe is CVE-2026-31072?
Critical severity. CVSS v3 base score is 9.8 out of 10.