CVE-2021-47952Public exploitNetwork attack vectorHinoki check available

Remote code execution via py/repr evaluation

Published May 16, 2026 · Updated May 16, 2026

Code injection in jsonpickle 2.0.0 allows remote attackers to execute arbitrary Python code through crafted py/repr JSON objects. The Unpickler's default unsafe path sends each py/repr value to loadrepr(), which imports its named module and passes the remaining expression to eval(). Exploitation requires an application to decode attacker-controlled JSON without enabling safe mode, and code runs with that application's privileges.

CVSS severity9.3
Critical
EPSS probability0.70%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Code injection in jsonpickle 2.0.0 allows remote attackers to execute arbitrary Python code through crafted py/repr JSON objects. The Unpickler's default unsafe path sends each py/repr value to loadrepr(), which imports its named module and passes the remaining expression to eval(). Exploitation requires an application to decode attacker-controlled JSON without enabling safe mode, and code runs with that application's privileges.

The record

CVE
CVE-2021-47952
Published
May 16, 2026
Updated
May 16, 2026
Vendor
jsonpickle
Product
jsonpickle
Classifications
CWE-502, CWE-94, T1059
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 16, 2026CVE publishedPublication date reported by the CVE source.
  2. May 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

jsonpickle · jsonpickleversion=2.0.0

Published CVSS scores

9.8VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.3VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
CWE-94Improper Control of Generation of Code ('Code Injection')
T1059Command and Scripting Interpreter

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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