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CVE Record

CVE-2026-31072: The JSONSerializer and CBORSerializer in APScheduler (all versions including 3.10.x and 4.0.0a5) are vulner...

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

CriticalCVSS 9.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

CVE-2026-31072 is a critical APScheduler deserialization flaw. Applications using its JSON or CBOR serializers may execute attacker-controlled code if hostile serialized data reaches the vulnerable unmarshalling path. Business risk is highest for internet-facing services or APIs that let users influence scheduler payloads or stored job data.

Executive priority

Treat as urgent for externally reachable Python services using APScheduler serialization. Prioritize inventory and exposure confirmation immediately, then apply vendor guidance when available.

Technical view

APScheduler JSONSerializer and CBORSerializer reportedly allow arbitrary class instantiation and state injection through unmarshal_object. The function dynamically imports modules and invokes __setstate__ on available classes. The CVE describes all versions including 3.10.x and 4.0.0a5 as affected, with CVSS 9.8 and CWE-502.

Likely exposure

Python applications using APScheduler with JSONSerializer or CBORSerializer are the primary concern. Exposure depends on whether attackers can submit, modify, or influence JSON or CBOR data that APScheduler later deserializes.

Exploitation context

The source bundle does not show KEV listing or cited evidence of active exploitation. Exploitation requires crafted JSON or CBOR reaching vulnerable APScheduler serializer unmarshalling in an affected application context.

Researcher notes

Affected-product metadata in the bundle is incomplete, but the description names APScheduler serializers directly. No patch, workaround, or exploitation evidence is included beyond references, so validation should focus on real data-flow reachability.

Mitigation direction

  • Check APScheduler and distribution vendor guidance for fixed versions or official workarounds.
  • Do not deserialize scheduler JSON or CBOR from untrusted sources.
  • Restrict who can create or modify scheduled job data.
  • Run affected services with least privilege and strong isolation.
  • Monitor Red Hat and APScheduler advisories for remediation status.

Validation and detection

  • Inventory applications and SBOMs for APScheduler usage.
  • Inspect configuration for JSONSerializer or CBORSerializer.
  • Trace whether external input can reach APScheduler serialized job data.
  • Review lockfiles for APScheduler 3.10.x, 4.0.0a5, or other versions.
  • Check vendor advisories for package-specific impact and fixes.
Prepared
Confidence
medium
Sources
7

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · medium confidence lookup

CWE-502: Code execution behavior lookup

Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
description · low confidence lookup

Execution behavior lookup

The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-31072 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Critical
CVSS
9.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
6Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: pocAutomatable: yesTechnical Impact: total

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
9.8CVSS 3.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9CISA-ADP
8.8CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H2.85.9redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

9.8Critical
CVSS 3.1 vector shape for CVE-2026-31072Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
cvssV3_1other:ssvc
redhat-SADPapscheduler: APScheduler: Remote Code Execution via Insecure Deserialization
other:Red Hat severity ratingcvssV3_1
  • 2026-05-19T16:01:02.483Z: Reported to Red Hat.
  • 2026-05-19T00:00:00.000Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

CWE-502

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-502 · source CWE mapping

Deserialization of Untrusted Data

Deserialization of Untrusted Data represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs