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CVE-2026-77401

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

Published: Sep 16, 2026Updated: Sep 16, 2026 Sources: CVE List NVDCWE-693

Description

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:HUI:NS:CC:HI:NA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:HPrivileges Required
High
UI:NUser Interaction
None
Scope
S:CScope
Changed
Impact
C:HConfidentiality
High
I:NIntegrity
None
A:NAvailability
None

Weaknesses

Affected Products

zopefoundation
oss-projectaka accesscontrol, restrictedpython, zope

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

References

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