CVE-2026-55830
RestrictedPython guard hooks can be shadowed via positional-only arguments
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High8.3 | CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:L |
| NVDNVD · Deferred | 3.1 | High8.3 | CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:L |
- EPSS (exploitation in 30 days)
- 0.29% · top 79% of all CVEs (5 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.3.
Weakness
Affected products
zopefoundation · RestrictedPython
- affected < 8.3
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPIRestrictedPythonGHSA-ffg3-p8fm-mjx2 (opens in a new tab)
References (2)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-ffg3-p8fm-mjx2 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-55830)Record last updated .