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

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-77401
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-16 15:17:46 UTC
Updated2026-09-16 19:17:38 UTC
DescriptionZope 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.

Risk And Classification

Primary CVSS: v3.1 6.8 MEDIUM from [email protected]

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

Problem Types: CWE-693 | CWE-693 CWE-693: Protection Mechanism Failure

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary6.8MEDIUMCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N
3.1CNADECLARED6.8MEDIUMCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
None
Availability
None

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Zopefoundation AccessControl affected < 7.4 Not specified

References

ReferenceSourceLinkTags
github.com/zopefoundation/AccessControl/security/advisories/GHSA-pq59-9f... [email protected] github.com
github.com/zopefoundation/AccessControl/releases/tag/7.4 [email protected] github.com
github.com/zopefoundation/AccessControl/commit/f980450eea416718be62847f3... [email protected] github.com
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