# CVE-2025-70559: Insecure Deserialization (pickle) in pdfminer.six CMap Loader — Local Privesc

> An attacker can achieve arbitrary code execution or privilege escalation by placing a malicious pickle file in a location accessible to the pdfminer.six library.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 3 Feb 2026
- **Updated:** 11 Feb 2026
- **Also known as:** DEBIAN-CVE-2025-70559, DLA-4374-2, GHSA-f83h-ghpp-7wcc, OESA-2026-4210, OESA-2026-4211, PYSEC-2026-1761, UBUNTU-CVE-2025-70559

## What is CVE-2025-70559?

CVE-2025-70559 is a medium-severity unsafe deserialization vulnerability in n/a, published on 3 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2025-70559?

3 open source packages ship an affected version, including pdfminer-six and pdfminer.six.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `pdfminer-six` | PyPI | All versions | 20251230 |
| `pdfminer-six` | PyPI | All versions | 20251230 |
| `pdfminer.six` | PyPI | All versions | 20251230 |

## How do I fix CVE-2025-70559?

Upgrade pdfminer-six to 20251230 or later.

## Is CVE-2025-70559 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-70559 exists.

Public exploit code:

- https://github.com/isukasanuj/CVE-2025-70559 (github_poc): https://github.com/isukasanuj/CVE-2025-70559

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-70559 and fix it if it is affected.

What it is: CVE-2025-70559 is a medium-severity unsafe deserialization vulnerability in n/a, published on 3 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-70559 exists.

Affected packages and fixed versions:
- pdfminer-six (PyPI): affected all versions; fixed in 20251230
- pdfminer-six (PyPI): affected all versions; fixed in 20251230
- pdfminer.six (PyPI): affected all versions; fixed in 20251230

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-70559/ (Markdown: https://insights.sbomify.com/CVE-2025-70559/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-70559
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-70559
- OSV: https://osv.dev/vulnerability/CVE-2025-70559

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-70559/
Summaries are generated and may contain mistakes; the official description above is the record.