Resource exhaustion in deepdiff - CVE-2026-33155
Published: May 21, 2026
Vulnerability identifier: #VU132003
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-33155
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to 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. A remote attacker can trigger resource exhaustion and perform a denial of service (DoS) attack.
Affected software
deepdiff
IBM Watson Discovery for IBM Cloud Pak for Data
openSUSE Leap
python311-deepdiff
IBM Watson Discovery for IBM Cloud Pak for Data
openSUSE Leap
python311-deepdiff
How to mitigate CVE-2026-33155
Install updates from vendor's website.
deepdiff - update to 8.6.2
IBM Watson Discovery for IBM Cloud Pak for Data - update to 5.3.2
python311-deepdiff - update to 6.3.0-150600.3.6.1
IBM Watson Discovery for IBM Cloud Pak for Data - update to 5.3.2
python311-deepdiff - update to 6.3.0-150600.3.6.1