CVE-2025-71343
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 · uneditedpicklescan before 0.0.30 fails to detect malicious pickle files that exploit lib2to3.pgen2.pgen.ParserGenerator.make_label function in the reduce method. Attackers can craft malicious pickle files with embedded code that evades detection but executes arbitrary commands when pickle.load() is called.
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 confidencepicklescan before version 0.0.30 fails to detect malicious pickle files that exploit the lib2to3.pgen2.pgen.ParserGenerator.make_label function within the reduce method. Attackers can craft pickle files containing embedded malicious code that bypass the scanner's detection mechanisms but achieve arbitrary command execution when the victim calls pickle.load().
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
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
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 picklescan installationRun 'pip show picklescan' or 'pip list | grep picklescan' to find if picklescan is installed in your environmentAffected if picklescan is not installed - no scanning capability exists
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Determine installed picklescan versionRun 'pip show picklescan' and note the Version field, or check the package metadataAffected if Version is lower than 0.0.30 (e.g., 0.0.29, 0.0.28, etc.) - the scanner is vulnerable to this bypass
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Verify detection capability against test payloadCreate a test pickle file that uses the lib2to3.pgen2.pgen.ParserGenerator.make_label technique in the reduce method, then scan it with picklescan using 'picklescan <file>'Affected if picklescan reports the file as safe or clean - the bypass is working and the version is vulnerable
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Review pickle.load usage in your codeSearch codebase for 'pickle.load' or 'pickle.loads' calls and inspect whether they process data from untrusted sourcesAffected if Your application deserializes untrusted pickle data - you are at risk even if picklescan is updated
You are affected if picklescan version is below 0.0.30 AND you rely on picklescan to detect malicious pickle files from untrusted sources.
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.
dbcve · scopedUpgrade picklescan to version 0.0.30 or later to obtain the detection signature for this evasion technique, and implement defense-in-depth by avoiding pickle deserialization of untrusted data or using restricted unpicklers.
picklescan 0.0.30
- Identify the current version of picklescan in your environment using pip show picklescan or your package manager
- Upgrade picklescan to version 0.0.30 or later using: pip install picklescan>=0.0.30
- Verify the upgrade was successful by running: pip show picklescan and confirming the version number
- If you use picklescan in automated scanning workflows, test that the upgrade does not break existing functionality with a sample pickle file scan
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,408.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-71343 — 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-2025-71343 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
- No spam, self-promotion, credentials, or personal data