HighVulnerability

CVE-2021-41220: TensorFlow memory leak and use after free in async CollectiveReduceV2

Source: NVD(opens in a new tab)
Identifier: CVE-2021-41220
Published: November 5, 2021
Record updated: October 9, 2026

Affected: tensorflow = 2.6.0
tensorflow-cpu = 2.6.0
tensorflow-gpu = 2.6.0
Fixed in: 2.6.1
tensorflow 2.6.1 released November 1, 2021, 5 days before disclosure
tensorflow-cpu 2.6.1 released November 1, 2021, 5 days before disclosure
tensorflow-gpu 2.6.1 released November 1, 2021, 5 days before disclosure
Known exploitation: Not listed in the CISA Known Exploited Vulnerabilities catalog at the last check.
EPSS: 0.2%

Summary

CVE-2021-41220 affects TensorFlow, an open source machine learning platform. In affected versions, the async implementation of `CollectiveReduceV2` has a memory leak and a use after free, caused by asynchronous computation and by accessing objects after they have been `std::move()`d from. The weakness is classified as CWE-416.

Mitigation

The fix will be included in TensorFlow 2.7.0, and the commit will also be cherrypicked onto TensorFlow 2.6.1, the only other affected version.

Details

Scores and exploitation

CVSS score: 7.8(high)
Patch available: Yes
EPSS: 0.2%Estimated probability that this CVE is exploited in the next 30 days, from the FIRST Exploit Prediction Scoring System. Read on November 4, 2026.

Weaknesses and techniques

Weakness (CWE): CWE-416
Attack pattern (CAPEC): CAPEC-233

Affected

Packages: tensorflow@= 2.6.0 (fixed: 2.6.1)
tensorflow-cpu@= 2.6.0 (fixed: 2.6.1)
tensorflow-gpu@= 2.6.0 (fixed: 2.6.1)
Vendors: Google

Classification

Attack type: Denial of service
Attack sophistication: Moderate
AI component targeted: Framework
Impact: Confidentiality,
Availability
Labels: security

How this record was produced

Summaries, mitigations and labels on this page are generated automatically from the source. The linked source is authoritative. The source gives this advisory a description and no title, so the title above is a headline generated from the source text.

Original source: https://nvd.nist.gov/vuln/detail/CVE-2021-41220

First tracked: February 15, 2026 at 08:40 PM ET, from NVD/CVE Database

Classifier: claude-haiku-5-5, prompt v4

Classifier confidence: 90% (self-assessed)

Affected packages in the Exposure Registry

Matched by package name and ecosystem. Each entry shows whether the package delegates to a language model and how many tracked packages depend on it.

tensorflowPyPINo LLM dependency detected · 26 tracked dependents
tensorflow-gpuPyPINo LLM dependency detected · 2 tracked dependents

Summary

Mitigation

Affected packages in the Exposure Registry

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