How severe is CVE-2021-41197?

CVE-2021-41197 has a CVSS score of 5.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-41197?

CVE-2021-41197 affects the following packages: tensorflow (PyPI), tensorflow (PyPI), tensorflow (PyPI), tensorflow-cpu (PyPI), tensorflow-cpu (PyPI), tensorflow-cpu (PyPI), tensorflow-gpu (PyPI), tensorflow-gpu (PyPI), and 1 more. Ecosystems affected: PyPI.

How do I fix CVE-2021-41197?

Update tensorflow to 2.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-41197 is resolved across your whole dependency graph.

How do I detect CVE-2021-41197 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tensorflow, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-41197 if there is no patch (or I can't update yet)?

Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

Is CVE-2021-41197 actively exploited in the wild?

Yes. There are 2 known exploit references for CVE-2021-41197, including 2 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2021-41197?

CVE-2021-41197 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 23th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-41197?

CVE-2021-41197 is classified as CWE-190 (CWE-190). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-41197 published, and has it been updated?

CVE-2021-41197 was published on November 5, 2021 and was last updated on August 7, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

MEDIUM severity

CVE-2021-41197 — tensorflow

MEDIUMFix: tensorflow/tensorflow@7c1692b

CVE-2021-41197 is a medium-severity (CVSS 5.5) CWE-190 vulnerability in tensorflow. 2 public exploit references exist, so weaponization risk is real. A fix is available for tensorflow — see the affected versions and patch details below.

Crashes due to overflow and `CHECK`-fail in ops with large tensor shapes

Also known asBIT-tensorflow-2021-41197GHSA-prcg-wp5q-rv7pPYSEC-2021-390PYSEC-2021-607PYSEC-2021-805

Published

Nov 5, 2021

Updated

Aug 7, 2026

Affected

9 pkgs

Patched

9 / 9

Exploits

2 known

Exploitation data as of Oct 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs23th percentile — riskier than 23% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2021-41197 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

9 pkgs affected

🐍tensorflow🐍tensorflow🐍tensorflow🐍tensorflow-cpu🐍tensorflow-cpu🐍tensorflow-cpu🐍tensorflow-gpu🐍tensorflow-gpu+1 more

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Impact

TensorFlow allows tensor to have a large number of dimensions and each dimension can be as large as desired. However, the total number of elements in a tensor must fit within an int64_t. If an overflow occurs, MultiplyWithoutOverflow would return a negative result. In the majority of TensorFlow codebase this then results in a CHECK-failure. Newer constructs exist which return a Status instead of crashing the binary.

For example AddDim calls should be replaced by AddDimWithStatus.

This is similar to CVE-2021-29584 (and similar other reported vulnerabilities in TensorFlow, localized to specific APIs).

Patches

We have patched the issue in GitHub commits 7c1692bd417eb4f9b33ead749a41166d6080af85 (merging #51732), d81b1351da3e8c884ff836b64458d94e4a157c15 (merging #51717), a871989d7b6c18cdebf2fb4f0e5c5b62fbc19edf (merging #51658), and d81b1351da3e8c884ff836b64458d94e4a157c15 (merging #51973). It is possible that other similar instances exist in TensorFlow, we will issue fixes as these are discovered.

The fix will be included in TensorFlow 2.7.0. We will also cherrypick this commit on TensorFlow 2.6.1, TensorFlow 2.5.2, and TensorFlow 2.4.4, as these are also affected and still in supported range.

For more information

Please consult our security guide for more information regarding the security model and how to contact us with issues and questions.

Attribution

This vulnerability has been reported externally via GitHub issue, GitHub issue and GitHub issue.

Affected Packages

9 total 9 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`tensorflow`	≥ 2.6.0&&< 2.6.1	2.6.1`pip install --upgrade 'tensorflow==2.6.1'`
🐍PyPI	`tensorflow`	≥ 2.5.0&&< 2.5.2	2.5.2`pip install --upgrade 'tensorflow==2.5.2'`
🐍PyPI	`tensorflow`	all versions	2.4.4`pip install --upgrade 'tensorflow==2.4.4'`
🐍PyPI	`tensorflow-cpu`	≥ 2.6.0&&< 2.6.1	2.6.1`pip install --upgrade 'tensorflow-cpu==2.6.1'`
🐍PyPI	`tensorflow-cpu`	≥ 2.5.0&&< 2.5.2	2.5.2`pip install --upgrade 'tensorflow-cpu==2.5.2'`
🐍PyPI	`tensorflow-cpu`	all versions	2.4.4`pip install --upgrade 'tensorflow-cpu==2.4.4'`

Affected Products

1 product · 3 configurations

Application

tensorflowgoogle

≥ 2.6.0 && < 2.6.1

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

TensorFlow is an open source platform for machine learning. In affected …

github.comNVDNov 2021

TensorFlow is an open source platform for machine learning. In affected …

github.comNVDNov 2021

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tensorflow, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update tensorflow to 2.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-41197 is resolved across your whole dependency graph.
Workarounds
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

Frequently Asked Questions

### Impact TensorFlow allows tensor to have a large number of dimensions and each dimension can be as large as desired. However, the total number of elements in a tensor must fit within an `int64_t`. If an overflow occurs, `MultiplyWithoutOverflow` would return a negative result. In the majority of TensorFlow codebase this then results in a `CHECK`-failure. Newer constructs exist which return a `Status` instead of crashing the binary. For example [`AddDim`](https://github.com/tensorflow/tensorflow/blob/0b6b491d21d6a4eb5fbab1cca565bc1e94ca9543/tensorflow/core/framework/tensor_shape.cc#L395-L40

O3 Security · Impact-Aware SCA

Is CVE-2021-41197 in your dependencies?

Find it across PyPI, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

5.5/10CVSS v3 base

Vector breakdown

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Raw vector

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

CWE Classification

CWE-190CWE-190

Weaponization

No known public exploit tooling found.

OpenSSF Scorecard

Package health score

tensorflow

7.8/10

Code-Review7/10

Maintained10/10

Dependency-Update-Tool10/10

Branch-ProtectionN/A

Vulnerabilities0/10

Assessed Oct 9, 2026

Timeline

Disclosed

Nov 5, 2021

First exploit

Nov 9, 2021

4 days after disclosure — rapid exploitation

Last updated

Aug 7, 2026

Identifiers

CVE-2021-41197

GHSA-prcg-wp5q-rv7p

BIT-tensorflow-2021-41197

PYSEC-2021-390

PYSEC-2021-607

References

Advisorynvd.nist.gov Fixgithub.com Fixgithub.com Fixgithub.com Fixgithub.com Webgithub.com Webgithub.com Webgithub.com Packagegithub.com Evidencegithub.com Evidencegithub.com

Related vulnerabilities

This CVE is medium severity; 8 of 8 other CVEs affecting tensorflow are rated as high or higher (top: high).

CVE-2023-33976CVE-2023-25661CVE-2023-25670CVE-2023-25665CVE-2023-27579CVE-2023-25673CVE-2023-25663CVE-2023-25658

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedAug 7, 2026

CVE-2021-41197 — tensorflow

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Impact

Patches

For more information

Attribution

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2021-41197 in your dependencies?