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Medium

Information disclosure in AccessControl

  • Disclosed: 07.09.2023
  • Updated: 11.10.2026 14:18

Impact

Python's "format" functionality allows someone controlling the format string to "read" objects accessible (recursively) via attribute access and subscription from accessible objects. Those attribute accesses and subscriptions use Python's full blown getattr and getitem, not the policy restricted AccessControl variants _getattr_ and _getitem_. This can lead to critical information disclosure.

AccessControl already provides a safe variant for str.format and denies access to string.Formatter. However, str.format_map is still unsafe.

Affected are all users who allow untrusted users to create AccessControl controlled Python code and execute it.

Patches

A fix will be introduced in the versions 4.4, 5.8 and 6.2.

Workarounds

There are no workarounds.

References

https://github.com/zopefoundation/RestrictedPython/security/advisories/GHSA-xjw2-6jm9-rf67 describes the corresponding problem for RestrictedPython.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Python (PyPI) accesscontrol < 4.4, >= 5.0, < 5.8, >= 6.0, < 6.2 4.4, 5.8, 6.2
Python (PyPI) zope < 4.8.9, >= 5.0.0, < 5.8.4 4.8.9, 5.8.4

References

CVSS score 6.8/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N
Weakness (CWE)
CWE-200
Platform
Python (PyPI)
Package
accesscontrol, zope
Disclosed
07.09.2023
Updated
11.10.2026 14:18

Sources and licenses

OSV / GitHub Advisory Database - PYSEC-2026-2075 - PyPA Advisory Database; CC BY 4.0

OSV / GitHub Advisory Database - GHSA-8xv7-89vj-q48c - CC BY 4.0

OSV / GitHub Advisory Database - PYSEC-2026-2325 - PyPA Advisory Database; CC BY 4.0

Vulnerability history: accesscontrol

All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.

Total entries
5
First → latest
07.2021 09.2026
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • Critical 1
  • High 1
  • Medium 3

Disclosures per year

  1. Zope AccessControl vulnerable to information disclosure through Python string `format` and `format_map` functions
    Medium · 6.8 CVE-2026-77401 < 7.4 7.4
  2. Access control vulnerable to user data deletion by anonynmous users
    Critical · 9.1 CVE-2024-51734 < 7.2 7.2
  3. Information disclosure in AccessControl this entry
    Medium · 6.8 CVE-2023-41050 < 4.4, >= 5.0, < 5.8, >= 6.0, < 6.2 4.4, 5.8, 6.2
  4. Zope is an open-source web application server. Zope versions prior to versions 4.6.3 and 5.3 have a remote code execution security issue. In order to be affected, one must use Python 3 for one's Zope
    High · 7.5 CVE-2021-32811 >= 4.0, < 4.3, >= 5.0, < 5.2 4.3, 5.2
  5. The module `AccessControl` defines security policies for Python code used in restricted code within Zope applications. Restricted code is any code that resides in Zope's object database, such as the c
    Medium · 4.4 CVE-2021-32807 >= 4.0, < 4.3, >= 5.0, < 5.2 4.3, 5.2

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