CVE-2026-55830CWE-184

RestrictedPython guard hooks can be shadowed via positional-only arguments

High · published July 8, 2026

CVSS v3.1
8.3
EPSS
0%
Percentile
33.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.3 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:L
CVSS v4.0
Not supplied
EPSS
0.00401 · 33.2th percentile
Weakness
CWE-184 · Incomplete List of Disallowed Inputs
Published
2026-07-08T21:16Z
EPSS history
Timeline
  • 08 JUL 21:16Z
    RestrictedPython guard hooks can be shadowed via positional-only arguments
    cvelistv5