APScheduler's JSONSerializer and CBORSerializer are vulnerable to Remote Code Execution (RCE) via Insecure
Affects apschedulerSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical.
Data as of 27 Oct 2026, 17:43 UTC
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 19 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| PyPIapscheduler | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Red Hat does not ship affected versions and thus does not provide fixes. Users should avoid using these vulnerable versions of APScheduler. If upgrading is possible, move to a version that does not include the vulnerable serializers or apply any vendor-provided mitigations once available. Monitor vendor advisories for updates. Avoid deserializing untrusted data with these serializers.
Description
APScheduler versions 4.0.0a1 through 4.0.0a6 contain a critical remote code execution vulnerability in their JSONSerializer and CBORSerializer components due to insecure deserialization. The vulnerability arises from the unmarshal_object function, which allows arbitrary class instantiation and state injection by dynamically importing modules and invoking __setstate__ on any class in the Python environment. An attacker can exploit this by sending a specially crafted JSON or CBOR payload to an application using these serializers, potentially leading to full system compromise. Red Hat does not ship affected versions and no fix is currently provided by them.
References
- nvd.nist.gov/vuln/detail/CVE-2026-31072 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-31072 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2479907 (opens in a new tab)
- gist.github.com/nedlir/11fb77f35a59cbba73392a086b02a9c6 (opens in a new tab)
- github.com/agronholm/apscheduler (opens in a new tab)
- github.com/pypa/advisory-database/tree/main/vulns/apscheduler/PYSEC-2026-282.yaml (opens in a new tab)
- pypi.org/project/apscheduler (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31072.json (opens in a new tab)