CVE-2021-47952
CVE-2021-47952 is a critical-severity vulnerability with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-94.
Key facts
- Severity: Critical (CVSS 3.x base score 9.8)
- CVSS v4: 9.3
- EPSS exploit prediction: 1% (49th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2021-34842
- Weakness: CWE-94
- Published:
- Last modified:
Description
python jsonpickle 2.0.0 contains a remote code execution vulnerability that allows attackers to execute arbitrary Python commands by deserializing malicious JSON payloads containing py/repr objects. Attackers can craft JSON strings with py/repr directives that invoke the eval function during deserialization to execute arbitrary code.
Frequently asked questions
- What is CVE-2021-47952?
- python jsonpickle 2.0.0 contains a remote code execution vulnerability that allows attackers to execute arbitrary Python commands by deserializing malicious JSON payloads containing py/repr objects. Attackers can craft JSON strings with py/repr directives that invoke the eval function during deserialization to execute arbitrary code.
- How severe is CVE-2021-47952?
- CVE-2021-47952 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2021-47952 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2021-47952?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- Does CVE-2021-47952 have an EU (EUVD) identifier?
- Yes. CVE-2021-47952 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34842.
- When was CVE-2021-47952 published?
- CVE-2021-47952 was published on 2026-05-16 and last updated on 2026-06-27.
References
- https://github.com/jsonpickle/jsonpickle
- https://jsonpickle.github.io
- https://www.exploit-db.com/exploits/49585
- https://www.vulncheck.com/advisories/python-jsonpickle-remote-code-execution-via-py-repr
- https://access.redhat.com/security/cve/CVE-2021-47952
- https://bugzilla.redhat.com/show_bug.cgi?id=2478170
- https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-47952.json
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