DeepdiffApplication · Qluster

CVE-2026-33155

HIGH · 7.5 CVSS v3.1 Published 2026-03-20
Fix available
A fix is available. Upgrade to 8.6.2 or later.
See remediation →
84/100
Remediation priority · High
Public exploit Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-400

A single request can consume unbounded CPU, memory, or connections, so a modest amount of malicious traffic exhausts the service. The result is denial of service for everyone else. Remediation is enforcing limits, quotas, and timeouts on what any one request can use.

General guidance for the uncontrolled resource consumption class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
DeepdiffApplication
Affected:>= 5.0.0, < 8.6.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 8.6.2 or later
Fixed in 8.6.2
Vendor patch github.com →
Recommended fix High confidence

8.6.2 or later

  1. Verify current deepdiff version by running: pip show deepdiff or pip list | grep deepdiff
  2. Upgrade deepdiff to version 8.6.2 or later using: pip install --upgrade deepdiff>=8.6.2
  3. Verify the upgrade was successful by running: pip show deepdiff
  4. If using pipfile or requirements.txt, update the deepdiff line to: deepdiff>=8.6.2
  5. After upgrading, test that your application still functions correctly, particularly any code using pickle_load or loading delta objects
Caveat Minor version upgrade within 8.x - low risk of breaking changes, but test thoroughly especially if using custom pickle handling

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,950. Get the upgrade done

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-33155 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data