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GHSA-cqv6-3phm-hcwx

HIGH

Access to invalid memory during shape inference in `Cudnn*` ops

Also known asBIT-tensorflow-2021-41221CVE-2021-41221PYSEC-2021-413PYSEC-2021-630PYSEC-2021-828
Published
Nov 10, 2021
Updated
Mar 13, 2026
Affected
9 pkgs
Patched
9 / 9
Exploits
1 known

EPSS Exploitation Probability

via FIRST.org ↗
0.2%probability of exploitation in next 30 days
Lower Risk12th percentile+0.19%
0.00%0.24%0.48%0.71%0.0%0.2%Dec 25Apr 26Jun 26

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

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

The shape inference code for the Cudnn* operations in TensorFlow can be tricked into accessing invalid memory, via a heap buffer overflow:

import tensorflow as tf

@tf.function
def func():
  return tf.raw_ops.CudnnRNNV3(
    input=[0.1, 0.1],
    input_h=[0.5],
    input_c=[0.1, 0.1, 0.1], 
    params=[0.5, 0.5],
    sequence_lengths=[-1, 0, 1])
  
func() 

This occurs because the ranks of the input, input_h and input_c parameters are not validated, but code assumes they have certain values:

auto input_shape = c->input(0);
auto input_h_shape = c->input(1);
auto seq_length = c->Dim(input_shape, 0);
auto batch_size = c->Dim(input_shape, 1);  // assumes rank >= 2
auto num_units = c->Dim(input_h_shape, 2); // assumes rank >= 3

Patches

We have patched the issue in GitHub commit af5fcebb37c8b5d71c237f4e59c6477015c78ce6.

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 by members of the Aivul Team from Qihoo 360.

Affected Packages

9 total 9 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPItensorflow2.6.0&&< 2.6.12.6.1
🐍PyPItensorflow2.5.0&&< 2.5.22.5.2
🐍PyPItensorflowall versions2.4.4
🐍PyPItensorflow-cpu2.6.0&&< 2.6.12.6.1
🐍PyPItensorflow-cpu2.5.0&&< 2.5.22.5.2
🐍PyPItensorflow-cpuall versions2.4.4
Exploits & PoCs
1

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

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. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update tensorflow to 2.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-cqv6-3phm-hcwx 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.

  4. How O3 protects you

    O3 pinpoints whether GHSA-cqv6-3phm-hcwx is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-cqv6-3phm-hcwx. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact The [shape inference code](https://github.com/tensorflow/tensorflow/blob/9ff27787893f76d6971dcd1552eb5270d254f31b/tensorflow/core/ops/cudnn_rnn_ops.cc) for the `Cudnn*` operations in TensorFlow can be tricked into accessing invalid memory, via a heap buffer overflow: ```python import tensorflow as tf @tf.function def func(): return tf.raw_ops.CudnnRNNV3( input=[0.1, 0.1], input_h=[0.5], input_c=[0.1, 0.1, 0.1], params=[0.5, 0.5], sequence_lengths=[-1, 0, 1]) func() ``` This occurs because the ranks of the `input`, `input_h` and `input_c` parameters ar
O3 Security · Impact-Aware SCA

Is GHSA-cqv6-3phm-hcwx in your dependencies?

O3 detects GHSA-cqv6-3phm-hcwx across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.