CVE-2021-41220Public exploit

Process crash via moved-from callback reuse

Published Nov 5, 2021 · Updated Aug 4, 2024

Use after free in Google TensorFlow 2.6.0 allows local users to crash a process or exhaust memory through malformed CollectiveReduceV2 inputs. The asynchronous kernel moves its completion callback into a cleanup closure but passes the moved-from callback to the error-handling macro, which invokes invalid state when input validation fails. The caller must be able to run a TensorFlow graph locally; documented effects are limited to a crash, allocation failure, or memory leakage.

CVSS severity7.8
High
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use after free in Google TensorFlow 2.6.0 allows local users to crash a process or exhaust memory through malformed CollectiveReduceV2 inputs. The asynchronous kernel moves its completion callback into a cleanup closure but passes the moved-from callback to the error-handling macro, which invokes invalid state when input validation fails. The caller must be able to run a TensorFlow graph locally; documented effects are limited to a crash, allocation failure, or memory leakage.

The record

CVE
CVE-2021-41220
Published
Nov 5, 2021
Updated
Aug 4, 2024
Vendor
Google
Product
TensorFlow
Classifications
CWE-416, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 5, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record 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.

  1. Affected versionversion=>= 2.6.0, < 2.6.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Google · TensorFlowversion=>= 2.6.0, < 2.6.1

Published CVSS scores

7.8NISTCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.2NISTAV:L/AC:L/Au:N/C:C/I:C/A:C

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1499.004Application or System Exploitation

Public exploit references

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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