CVE-2026-33155: DeepDiff has Memory Exhaustion DoS through SAFE_TO_IMPORT

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-03-20 · updated 2026-06-17
Weakness: CWE-400

Description

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.

Affected products

seperman deepdiff: from 5.0.0 before 8.6.2 — fixed in 8.6.2

How to fix

Upgrade to a fixed version: seperman deepdiff 8.6.2. Check the vendor advisory for mitigations.

References

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