# CVE-2025-71351: picklescan - Remote Code Execution via timeit.timeit() Detection Bypass

> Attackers can bypass picklescan detection using timeit.timeit() in pickle files to achieve remote code execution when the library processes malicious data.

- **Severity:** High 7.6 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 21 Jun 2026
- **Updated:** 22 Jun 2026
- **Also known as:** GHSA-v7x6-rv5q-mhwc, PYSEC-2026-4135

## What is CVE-2025-71351?

CVE-2025-71351 is a high-severity unsafe deserialization vulnerability in picklescan, published on 21 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

picklescan before 0.0.25 fails to detect malicious pickle files that use timeit.timeit() in the __reduce__ method, allowing remote code execution. Attackers can craft pickle files that import dangerous libraries like os and execute arbitrary system commands, which evade picklescan detection and execute when pickle.load() is called.

Weakness: CWE-184 (Incomplete List of Disallowed Inputs)

## Which versions are affected by CVE-2025-71351?

3 open source packages ship an affected version, including picklescan.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `picklescan` | PyPI | All versions | 0.0.25 |
| `picklescan` | PyPI | All versions | 0.0.25 |
| `picklescan` | PyPI | All versions | 0.0.25 |

## How do I fix CVE-2025-71351?

Upgrade picklescan to 0.0.25 or later.

## Is CVE-2025-71351 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-71351 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-71351 and fix it if it is affected.

What it is: CVE-2025-71351 is a high-severity unsafe deserialization vulnerability in picklescan, published on 21 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-71351 exists.

Affected packages and fixed versions:
- picklescan (PyPI): affected all versions; fixed in 0.0.25
- picklescan (PyPI): affected all versions; fixed in 0.0.25
- picklescan (PyPI): affected all versions; fixed in 0.0.25

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-2025-71351/ (Markdown: https://insights.sbomify.com/CVE-2025-71351/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-71351
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-71351
- OSV: https://osv.dev/vulnerability/CVE-2025-71351

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-71351/
Summaries are generated and may contain mistakes; the official description above is the record.