CVE-2021-47952
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedpython 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidencejsonpickle 2.0.0 is vulnerable to remote code execution through malicious JSON payloads containing py/repr directives. During deserialization, these special objects invoke Python's eval() function, allowing attackers to execute arbitrary Python commands on the target system.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify jsonpickle installation and versionRun 'pip show jsonpickle' or check your project dependencies (requirements.txt, setup.py, pyproject.toml) for jsonpickle and its versionAffected if jsonpickle version 2.0.0 is installed
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Locate jsonpickle deserialization codeSearch codebase for calls to jsonpickle.decode(), jsonpickle.loads(), or pickle methods that deserialize JSON dataAffected if Your code uses jsonpickle to deserialize JSON data
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Determine if input sources are untrustedReview code that feeds data into jsonpickle deserialization; check if input originates from user input, HTTP requests, APIs, files from external sources, or any source outside your trusted boundaryAffected if JSON data from untrusted or external sources is deserialized using jsonpickle
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Inspect for py/repr object handlingExamine deserialized output or logs for py/repr keys in JSON payloads; these appear as '{"py/repr": "..."}' patterns in processed dataAffected if Your application processes JSON containing py/repr directives
You are affected if jsonpickle 2.0.0 is installed AND your application deserializes JSON from untrusted sources using jsonpickle, as this allows malicious py/repr objects to trigger arbitrary code execution via eval.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpgrade jsonpickle to a patched version that disables or restricts py/repr evaluation. If immediate upgrading is not possible, implement strict input validation to reject JSON payloads containing py/repr objects before deserialization.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-47952 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-47952 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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