---
title: "CVE-2026-31072: APScheduler's JSONSerializer and CBORSerializer are vulnerable to Remote Code Execution (RCE) via Insecure Deserialization"
url: https://erroneo.us/security/cve/CVE-2026-31072/
description: "CVE-2026-31072 (apscheduler (PyPI)): The JSONSerializer and CBORSerializer in APScheduler (all versions including 3.10.x and 4.0.0a5) are vulnerable to…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-05-19
date_modified: 2026-07-15
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-31072"
kev: false
cvss: 8.8
epss: 0.01007
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-31072: APScheduler's JSONSerializer and CBORSerializer are vulnerable to Remote Code Execution (RCE) via Insecure Deserialization

**Signal:** Normal patch cycle. No exploitation signal; fix it in your next routine update if you are affected. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 1.0% , percentile 63: FIRST’s model estimates a 1.0% chance of exploitation activity in the next 30 days, higher than 63% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes apscheduler (PyPI) >= 4.0.0a1, <= 4.0.0a6, no fixed version listed . Check your lockfile, including transitive dependencies.

## What it is

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 unmarshalobject 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

## Affected packages

- PyPI `apscheduler` >= 4.0.0a1, <= 4.0.0a6 → fixed: none listed

## Affected products (CVE record)

- n/a n/a: see advisory

## Severity

- CISA-ADP CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- redhat-SADP CVSS 3.1: 8.8 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 1.01% probability of exploitation activity in the next 30 days; percentile 63.

## Sources

- [GitHub Advisory GHSA-9cfw-f3f9-7mm7](https://github.com/advisories/GHSA-9cfw-f3f9-7mm7)
- [CVE.org record CVE-2026-31072](https://www.cve.org/CVERecord?id=CVE-2026-31072)
- [NVD entry CVE-2026-31072](https://nvd.nist.gov/vuln/detail/CVE-2026-31072)
- [github.com](https://github.com/agronholm/apscheduler)
- [gist.github.com](https://gist.github.com/nedlir/11fb77f35a59cbba73392a086b02a9c6)
- [access.redhat.com](https://access.redhat.com/security/cve/CVE-2026-31072)
- [RHBZ#2479907](https://bugzilla.redhat.com/show_bug.cgi?id=2479907)
- [security.access.redhat.com](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31072.json)

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Source page: https://erroneo.us/security/cve/CVE-2026-31072/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt