CVE-2021-37656Public exploit

Undefined behavior via decreasing ragged splits

Published Aug 12, 2021 · Updated Aug 4, 2024

Undefined behavior in Google TensorFlow before 2.3.4, 2.4.0 through 2.4.2, and 2.5.0 allows local users to disrupt a process via ragged splits. RaggedTensorToSparse fails to reject decreasing rt_nested_splits values, then binds a C++ reference through a null pointer while converting the malformed tensor. The caller must be able to invoke the local TensorFlow operation with crafted tensor inputs; the resulting undefined behavior is confined to the hosting process.

CVSS severity7.1
High
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Undefined behavior in Google TensorFlow before 2.3.4, 2.4.0 through 2.4.2, and 2.5.0 allows local users to disrupt a process via ragged splits. RaggedTensorToSparse fails to reject decreasing rt_nested_splits values, then binds a C++ reference through a null pointer while converting the malformed tensor. The caller must be able to invoke the local TensorFlow operation with crafted tensor inputs; the resulting undefined behavior is confined to the hosting process.

The record

CVE
CVE-2021-37656
Published
Aug 12, 2021
Updated
Aug 4, 2024
Vendor
Google
Product
TensorFlow
Classifications
CWE-824, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 12, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.3.4
  2. Affected versionversion=>= 2.4.0, < 2.4.3
  3. Affected versionversion=>= 2.5.0, < 2.5.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Google · TensorFlowversion=< 2.3.4; version=>= 2.4.0, < 2.4.3; version=>= 2.5.0, < 2.5.1

Published CVSS scores

7.1GitHub, Inc.CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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-824Access of Uninitialized Pointer
T1499.004Endpoint Denial of Service: Application 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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