Bug 2449786 (CVE-2026-33155)

Summary:	CVE-2026-33155 deepdiff: python: DeepDiff: Denial of Service via unrestricted memory allocation in pickle unpickler
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	derez, jkoehler, kaycoth, lphiri
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in DeepDiff. A remote attacker could exploit a vulnerability in the `_RestrictedUnpickler` component, which fails to limit constructor arguments for certain data types. By providing a specially crafted, small pickle payload, an attacker can force the application to allocate an excessive amount of memory, leading to a denial of service (DoS) due to application crashes.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-03-20 21:02:48 UTC

DeepDiff is a project focused on Deep Difference and search of any Python data. From version 5.0.0 to before version 8.6.2, the pickle unpickler _RestrictedUnpickler validates which classes can be loaded but does not limit their constructor arguments. A few of the types in SAFE_TO_IMPORT have constructors that allocate memory proportional to their input (builtins.bytes, builtins.list, builtins.range). A 40-byte pickle payload can force 10+ GB of memory, which crashes applications that load delta objects or call pickle_load with untrusted data. This issue has been patched in version 8.6.2.