TI-2026-53992 Aliases CVE-2026-77401 GHSA-pq59-9fq7-m886

Zope AccessControl: Information disclosure through Python string `format` and `format_map` functions

LOW 30CWE-693Published 2026-09-16 · Updated 2026-09-16

Key facts

Attack vector: Network
Privileges required: High
User interaction: None
Attack complexity: Low
Impact type: Security bypass
Confidentiality · integrity · availability: High · None · None
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-693.

Summary

Zope AccessControl provides a general security framework for use in Zope. Prior to 7.4, applications that allow untrusted users to create and execute AccessControl-controlled Python code do not safely guard str.format and str.format_map when those methods are reached through a str subclass. In both ImplPython.py and cAccessControl.c, Python formatting can recursively access attributes and subscriptions using unrestricted getattr and getitem behavior instead of the policy-restricted getattr and getitem operations. A controlled format string can therefore disclose objects reachable from values available to the formatting operation. This issue is fixed in version 7.4.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00469 40th percentileScored 2026-11-07

Fix Fixed AccessControl (zopefoundation): 7.4AccessControl (PyPI): 7.4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

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	AccessControl	before 7.4	7.4	Patch available	CNA
—	AccessControl (PyPI)	before 7.4	7.4	Patch available	GHSA-pq59-9fq7-m886

AccessControl Vendorzopefoundation Affected before 7.4 Fixed in 7.4 Patch available CNA
AccessControl (PyPI) Vendor— Affected before 7.4 Fixed in 7.4 Patch available GHSA-pq59-9fq7-m886

Remediation

Fix · CNA AccessControl (zopefoundation) Fixed in 7.4
Fix · GHSA-pq59-9fq7-m886 AccessControl (PyPI) Fixed in 7.4 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-77401
2026-10-03 Alias added: GHSA-pq59-9fq7-m886

References

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2026-77401

Other 4

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-2026-40297 RestrictedPython guard hooks can be shadowed via positional-only arguments CVSS 3.1HIGH 8.3
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

See all 55 →

Sources

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