CVE-2025-70559
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 · uneditedpdfminer.six before 20251230 contains an insecure deserialization vulnerability in the CMap loading mechanism. The library uses Python pickle to deserialize CMap cache files without validation. An attacker with the ability to place a malicious pickle file in a location accessible to the application can trigger arbitrary code execution or privilege escalation when the file is loaded by a trusted process. This is caused by an incomplete patch to CVE-2025-64512.
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 confidencepdfminer.six before 20251230 insecurely deserializes CMap cache files using Python's pickle module without validation. An attacker who can place a malicious pickle file in a location the application accesses can achieve arbitrary code execution. This vulnerability stems from an incomplete fix for CVE-2025-64512.
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
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/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 installed pdfminer.six versionRun 'pip show pdfminer.six' or check your package manifest to find the installed version numberAffected if The version is earlier than 20251230 (e.g., 20241101, 20240630, etc.)
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Determine if CMap caching is in useInspect your pdfminer.six configuration or code that loads CMap files; look for CMap cache settings or the use of CMapDB methods that load from cacheAffected if CMap caching is enabled and pdfminer.six is loading CMap data from cache files at runtime
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Locate the CMap cache directoryCheck your application runtime for the default cache location (typically under the pdfminer package data directory) or any custom cache path your deployment may useAffected if The CMap cache directory exists and is accessible to the application process
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Verify cache directory permissionsReview file system permissions on the CMap cache directory to determine if untrusted users can write files to itAffected if The CMap cache directory is writable by users other than the application owner or untrusted processes can place files in it
You are affected if pdfminer.six version is before 20251230 AND your application deserializes CMap cache files using pickle without additional validation, especially if the cache directory has overly permissive write access.
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 pdfminer.six to version 20251230 or later. Additionally, ensure the CMap cache directory is not writable by untrusted users to prevent malicious pickle file placement.
pdfminer.six version 20251230 or later
- 1. Identify the current pdfminer.six version installed in your environment using 'pip show pdfminer.six' or 'pip list'
- 2. If the installed version is earlier than 20251230, upgrade to the latest version using 'pip install --upgrade pdfminer.six'
- 3. Verify the upgrade was successful by running 'pip show pdfminer.six' and confirming the version is 20251230 or later
- 4. If your application uses CMap caching, clear any existing cached CMap files to prevent loading of potentially malicious older cache files
- 5. Ensure that the application cannot be tricked into loading CMap files from untrusted locations by reviewing file access controls
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2025-70559 — 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-2025-70559 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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