CVSS 3.1
9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HCVE-2026-31072
Critical (9.8). EPSS 0.8% chance of exploitation in the next 30 days.
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
Severity
- EPSS
- 0.8% chance of exploitation in the next 30 days; higher than 56% of CVEs (scores of 2026-11-01)
- CWE
- CWE-502
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-9cfw-f3f9-7mm7 | PyPI | apscheduler | >=4.0.0a1 <=4.0.0a6 | no fix published |
| PYSEC-2026-282 | PyPI | apscheduler | >=4.0.0a1 <=4.0.0a6 | no fix published |