APScheduler 4.0.0a5 JSONSerializer/CBORSerializer unmarshal_object deserialization

CVSS Meta Temp Score
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CTI Interest Score
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7.9$0-$5k0.00

Summaryinfo

A vulnerability labeled as critical has been found in APScheduler 4.0.0a5. This affects the function unmarshal_object of the component JSONSerializer/CBORSerializer. Executing a manipulation can lead to deserialization. This vulnerability is handled as CVE-2026-31072. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in APScheduler 4.0.0a5. It has been declared as critical. This vulnerability affects the function unmarshal_object of the component JSONSerializer/CBORSerializer. The manipulation with an unknown input leads to a deserialization vulnerability. The CWE definition for the vulnerability is CWE-502. The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-31072 since 03/09/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 05/23/2026).

The vulnerability scanner Nessus provides a plugin with the ID 316452 (Linux Distros Unpatched Vulnerability : CVE-2026-31072), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at Tenable (316452). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.9

VulDB Base Score: 6.3
VulDB Temp Score: 6.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

ADP CISA Base Score: 9.8
ADP CISA Vector: 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Deserialization
CWE: CWE-502 / CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 316452
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-31072

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

03/09/2026 CVE reserved
05/19/2026 +70 days Advisory disclosed
05/19/2026 +0 days VulDB entry created
05/23/2026 +4 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Not defined

CVE: CVE-2026-31072 (🔒)
GCVE (CVE): GCVE-0-2026-31072
GCVE (VulDB): GCVE-100-364696

Entryinfo

Created: 05/19/2026 22:30
Updated: 05/23/2026 14:37
Changes: 05/19/2026 22:30 (52), 05/23/2026 01:48 (2), 05/23/2026 14:37 (11)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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