# CVE-2023-41039: restrictedpython: RestrictedPython is a restricted execution environment for Python to run untrusted code

CVE-2023-41039 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2023-41039, released August 30, 2023. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2023-41039
- Priority: High
- CVSS: 7.7 (high)
- EPSS: 0.0068
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 30, 2023

## Description

RestrictedPython is a restricted execution environment for Python to run untrusted code. Python's "format" functionality allows someone controlling the format string to "read" all objects accessible through recursive attribute lookup and subscription from objects he can access. This can lead to critical information disclosure. With `RestrictedPython`, the format functionality is available via the `format` and `format_map` methods of `str` (and `unicode`) (accessed either via the class or its instances) and via `string.Formatter`. All known versions of `RestrictedPython` are vulnerable. This issue has been addressed in commit `4134aedcff1` which has been included in the 5.4 and 6.2 releases. Users are advised to upgrade. There are no known workarounds for this vulnerability.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | python3-restrictedpython Ubuntu 20.04 LTS (focal) | 4.0~b3-2ubuntu0.1~esm1 | [python3-restrictedpython 4.0~b3-2ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-python3-restrictedpython-4.0-b3-2ubuntu0.1-esm1.md) | Sep 30, 2024 |
| Linux | python3-restrictedpython Ubuntu 22.04.1 LTS (jammy) | 4.0~b3-3ubuntu0.1~esm1 | [python3-restrictedpython 4.0~b3-3ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-python3-restrictedpython-4.0-b3-3ubuntu0.1-esm1.md) | Sep 30, 2024 |
| Linux | restrictedpython Debian 13.5 (trixie) | 6.2-1 | [DEBIAN-CVE-2023-41039](https://patchblox.com/security/data/fix/linux/debian-cve-2023-41039.md) | Aug 30, 2023 |
| Linux | restrictedpython Debian 14 | 6.2-1 | [DEBIAN-CVE-2023-41039](https://patchblox.com/security/data/fix/linux/debian-cve-2023-41039.md) | Aug 30, 2023 |

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Data as of 2026-11-09T19:38:12Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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