Code execution via unguarded metadata unpickling
Published Sep 23, 2026 · Updated Sep 23, 2026
Deserialization in Dask 2026.8.0 and earlier allows attackers to execute code when a crafted array-stack directory is loaded. The from_npy_stack function in dask/array/core.py passes the stack's info metadata file directly to pickle.load without validating its origin or contents. Exploitation requires an application or worker to load an attacker-supplied or attacker-modified stack directory, after which the pickle payload runs with that process's privileges.
Summary
What happened
Deserialization in Dask 2026.8.0 and earlier allows attackers to execute code when a crafted array-stack directory is loaded. The from_npy_stack function in dask/array/core.py passes the stack's info metadata file directly to pickle.load without validating its origin or contents. Exploitation requires an application or worker to load an attacker-supplied or attacker-modified stack directory, after which the pickle payload runs with that process's privileges.
The record
- CVE
- CVE-2026-95897
- Published
- Sep 23, 2026
- Updated
- Sep 23, 2026
- Vendor
- Dask
- Product
- Dask
- Classifications
- T1204.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 23, 2026CVE publishedPublication date reported by the CVE source.
- Sep 23, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=2026.0
- Affected versionversion=2026.1
- Affected versionversion=2026.2
- Affected versionversion=2026.3
- Affected versionversion=2026.4
- Affected versionversion=2026.5
- Affected versionversion=2026.6
- Affected versionversion=2026.7
- Affected versionversion=2026.8.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
- Dask from_npy_stack pickle proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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