TI-2026-40297 Aliases CVE-2026-55830 GHSA-ffg3-p8fm-mjx2

RestrictedPython guard hooks can be shadowed via positional-only arguments

HIGH 71CWE-184Published 2026-07-08 · Updated 2026-07-09

Key facts

Attack vector: Network
Privileges required: High
User interaction: Required
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: High · High · Low
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00287 21st percentileScored 2026-11-07

Fix Fixed RestrictedPython (zopefoundation): 8.3RestrictedPython (PyPI): 8.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: No
Technical impact: Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
zopefoundation	RestrictedPython	before 8.3	8.3	Patch available	CNA
—	RestrictedPython (PyPI)	before 8.3	8.3	Patch available	GHSA-ffg3-p8fm-mjx2

RestrictedPython Vendorzopefoundation Affected before 8.3 Fixed in 8.3 Patch available CNA
RestrictedPython (PyPI) Vendor— Affected before 8.3 Fixed in 8.3 Patch available GHSA-ffg3-p8fm-mjx2

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:a:zope:restrictedpython::::::::	—	—	zopefoundation

cpe:2.3:a:zope:restrictedpython:*:*:*:*:*:*:*:* Versions — — ·zopefoundation

Remediation

Fix · CNA RestrictedPython (zopefoundation) Fixed in 8.3
Fix · GHSA-ffg3-p8fm-mjx2 RestrictedPython (PyPI) Fixed in 8.3 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-55830
2026-10-03 Alias added: GHSA-ffg3-p8fm-mjx2

References

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2026-55830

Other 3

TI-2011-03162 Unspecified vulnerability in Zope 2.12.x and 2.13.x, as used in Plone 4.0.x through… CVSS 2.0HIGH 9.3
TI-2024-16328 Products.SQLAlchemyDA vulnerable to unauthenticated arbitrary SQL query execution CVSS 3.1CRITICAL 9.8
TI-2000-00062 The DTML implementation in the Z Object Publishing Environment (Zope) allows remote… CVSS 2.0HIGH 10.0
TI-2024-31821 RestrictedPython information leakage via `AttributeError.obj` and the `string` module CVSS 4.0HIGH 8.7
TI-2024-34640 User data deletion by anoynmous users in Zope CVSS 4.0HIGH 8.7
TI-2023-18901 RestrictedPython vulnerable to arbitrary code execution via stack frame sandbox escape CVSS 3.1CRITICAL 9.9

See all 55 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences