CVE-2026-31072
Published: May 19, 2026· Updated: May 20, 2026
Official Description
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
Risk Analysis
This critical vulnerability in APScheduler's JSONSerializer and CBORSerializer allows for remote code execution via insecure deserialization. With a CVSS score of 9.8, this flaw enables attackers to execute arbitrary code and fully compromise the system.
No public exploit is currently known for this vulnerability. Its remote exploitability and low attack complexity make it a high-risk issue.
Review and update APScheduler to a version that addresses this deserialization vulnerability. Implement secure serialization practices and restrict untrusted data deserialization.
Technical Analysis
CVE-2026-31072 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
All References (3)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-31072 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts