CVE-2026-55830

RestrictedPython guard hooks can be shadowed via positional-only arguments

Published Jul 8, 2026 CVSS 3.1 · 8.3 High EPSS < 1% KEV · Not listed
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. Prior to 8.3, check_function_argument_names() rejected protected guard hook names for regular, variadic, and keyword-only arguments but omitted positional-only arguments, allowing __getattr__, _getitem_, _write_, or _print_ to be shadowed by a local parameter and bypass the embedding application's access policy. This issue is fixed in version 8.3.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-ffg3-p8fm-mjx2 RestrictedPython guard hooks can be shadowed via positional-only arguments
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Zope
Zope restrictedpython
Vendors & Products Zope
Zope restrictedpython
Type Values Removed Values Added
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. Prior to 8.3, check_function_argument_names() rejected protected guard hook names for regular, variadic, and keyword-only arguments but omitted positional-only arguments, allowing __getattr__, _getitem_, _write_, or _print_ to be shadowed by a local parameter and bypass the embedding application's access policy. This issue is fixed in version 8.3.
Title RestrictedPython guard hooks can be shadowed via positional-only arguments
Weaknesses CWE-184
References
Metrics cvssV3_1

{'score': 8.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 9, 2026, 1:46 PM
Reserved
Jun 17, 2026, 4:29 PM
Status
Deferred
Published
Jul 8, 2026, 10:17 PM
Modified
Oct 25, 2026, 5:10 PM