Information disclosure in AccessControl

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.8 · CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N

EPSS

• CVE-2023-41050: 0.64% estimated exploitation activity in the next 30 days; percentile 50.74 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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.formatmap 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.

Published by the source

7 Sep 2023, 12:56 UTC

Last modified by the source

13 Jul 2026, 16:43 UTC

Source last checked

26 Oct 2026, 13:12 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-8xv7-89vj-q48c

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-8xv7-89vj-q48c

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2023-41050

Advisory: Information disclosure in AccessControl
IDs: CVE-2023-41050, GHSA-8xv7-89vj-q48c
Record: https://patchnext.com/advisories/cve-2023-41050 (revision 2, source checked 26 Oct 2026, 13:12 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: zope 5.8.4, 4.8.9; accesscontrol 6.2, 5.8, 4.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI zope: affected < 4.8.9; >= 5.0.0, < 5.8.4; fixed in 4.8.9, 5.8.4
- PyPI accesscontrol: affected < 4.4; >= 5.0, < 5.8; >= 6.0, < 6.2; fixed in 5.8, 6.2, 4.4

## Suggested inspection (read-only)
- `python -m pip show zope`: prints the installed version. Run with the environment that serves production active.
- `python -m pip show accesscontrol`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on zope, accesscontrol.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-8xv7-89vj-q48c (OSV record GHSA-8xv7-89vj-q48c lists affected ranges: PyPI accesscontrol >=0 =5.0 =6.0 =0 =5.0.0 <5.8.4 (fixed))
- Verified: https://github.com/advisories/GHSA-8xv7-89vj-q48c (GitHub-reviewed advisory GHSA-8xv7-89vj-q48c lists affected ranges: PyPI accesscontrol >=0 =5.0 =6.0 =0 =5.0.0 <5.8.4)

Commands are suggestions: review each one before running it.