Resource exhaustion in deepdiff - CVE-2026-33155

Detailed vulnerability description

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.

How to mitigate CVE-2026-33155

Sources

• https://github.com/qlustered/deepdiff/commit/0d07ec21d12b46ef4e489383b363eadc22d990fb
• https://github.com/qlustered/deepdiff/security/advisories/GHSA-54jj-px8x-5w5q