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HIGH severity

CVE-2021-37662 — tensorflow

HIGHFix: tensorflow/tensorflow@429f009

CVE-2021-37662 is a high-severity (CVSS 7.8) CWE-824 vulnerability in tensorflow. A fix is available for tensorflow — see the affected versions and patch details below.

Reference binding to nullptr in boosted trees

Also known asBIT-tensorflow-2021-37662GHSA-f5cx-5wr3-5qrcPYSEC-2021-284PYSEC-2021-575PYSEC-2021-773
Published
Updated
Affected
9 pkgs
Patched
9 / 9
Exploits
None indexed
Exploitation data as of Oct 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
0.2%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs8th percentile — riskier than 8% of all scored CVEsHighest risk
0.00%0.23%0.46%0.69%0.1%0.2%Apr 26Aug 26Oct 26

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

How urgent is this, really

CVE-2021-37662 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 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

An attacker can generate undefined behavior via a reference binding to nullptr in BoostedTreesCalculateBestGainsPerFeature:

import tensorflow as tf

tf.raw_ops.BoostedTreesCalculateBestGainsPerFeature(
  node_id_range=[],
  stats_summary_list=[[1,2,3]],
  l1=[1.0],
  l2=[1.0],
  tree_complexity =[1.0],
  min_node_weight =[1.17],
  max_splits=5)

A similar attack can occur in BoostedTreesCalculateBestFeatureSplitV2:

import tensorflow as tf
                                                                                                                                                                                                                                                                                          
tf.raw_ops.BoostedTreesCalculateBestFeatureSplitV2(
  node_id_range=[],
  stats_summaries_list=[[1,2,3]],
  split_types=[''],
  candidate_feature_ids=[1,2,3,4],
  l1=[1],     
  l2=[1],
  tree_complexity=[1.0],
  min_node_weight=[1.17],
  logits_dimension=5)

The implementation does not validate the input values.

Patches

We have patched the issue in GitHub commit 9c87c32c710d0b5b53dc6fd3bfde4046e1f7a5ad and in commit. 429f009d2b2c09028647dd4bb7b3f6f414bbaad7.

The fix will be included in TensorFlow 2.6.0. We will also cherrypick this commit on TensorFlow 2.5.1, TensorFlow 2.4.3, and TensorFlow 2.3.4, 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 by members of the Aivul Team from Qihoo 360.

Affected Packages

9 total 9 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPItensorflowall versions2.3.4pip install --upgrade 'tensorflow==2.3.4'
🐍PyPItensorflow≥ 2.4.0&&< 2.4.32.4.3pip install --upgrade 'tensorflow==2.4.3'
🐍PyPItensorflow≥ 2.5.0&&< 2.5.12.5.1pip install --upgrade 'tensorflow==2.5.1'
🐍PyPItensorflow-cpuall versions2.3.4pip install --upgrade 'tensorflow-cpu==2.3.4'
🐍PyPItensorflow-cpu≥ 2.4.0&&< 2.4.32.4.3pip install --upgrade 'tensorflow-cpu==2.4.3'
🐍PyPItensorflow-cpu≥ 2.5.0&&< 2.5.12.5.1pip install --upgrade 'tensorflow-cpu==2.5.1'

Affected Products

1 product · 6 configurations
Application
tensorflowgoogle
≥ 2.4.0 && < 2.4.3
2 versions
2.5.02.6.0

Detection & mitigation playbook

Open-source dependency
  1. 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.

  2. Fix

    Update tensorflow to 2.3.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-37662 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

### Impact An attacker can generate undefined behavior via a reference binding to nullptr in `BoostedTreesCalculateBestGainsPerFeature`: ```python import tensorflow as tf tf.raw_ops.BoostedTreesCalculateBestGainsPerFeature( node_id_range=[], stats_summary_list=[[1,2,3]], l1=[1.0], l2=[1.0], tree_complexity =[1.0], min_node_weight =[1.17], max_splits=5) ``` A similar attack can occur in `BoostedTreesCalculateBestFeatureSplitV2`: ```python import tensorflow as tf
O3 Security · Impact-Aware SCA

Is CVE-2021-37662 in your dependencies?

Find it across PyPI, including transitive dependencies.

CVE-2021-37662: tensorflow — Fixed in 2.3.4