🛡️ CVE-2021-37678 — tensorflow

🟠 CVSS 8.0 — High ✅ No Known Exploit CWE-502 OSV
8.0
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Arbitrary code execution due to YAML deserialization

Impact

TensorFlow and Keras can be tricked to perform arbitrary code execution when deserializing a Keras model from YAML format.

```python

from tensorflow.keras import models

payload = '''

!!python/object/new:type

args: ['z', !!python/tuple [], {'extend': !!python/name:exec }]

listitems: "__import__('os').system('cat /etc/passwd')"

'''

models.model_from_yaml(payload)

```

The [implementation](https://github.com/tensorflow/tensorflow/blob/460e000de3a83278fb00b61a16d161b1964f15f4/tensorflow/python/keras/saving/model_config.py#L66-L104) uses yaml.unsafe_load which can perform arbitrary code execution on the input.

Patches

Given that YAML format support requires a significant amount of work, we have removed it for now.

We have patched the issue in GitHub commit [23d6383eb6c14084a8fc3bdf164043b974818012](https://github.com/tensorflow/tensorflow/commit/23d6383eb6c14084a8fc3bdf164043b974818012).

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](https://github.com/tensorflow/tensorflow/blob/master/SECURITY.md) for more information regarding the security model and how to contact us with issues and questions.

Attribution

This vulnerability has been reported by Arjun Shibu.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. Rated impact: confidentiality high, integrity high, availability high.

Weakness class

CVE-2021-37678 is classified as CWE-502: Deserialization of Untrusted Data. Serialised data from an untrusted source is reconstructed into objects, which can trigger code during the process.

Affected software

CVE-2021-37678 is recorded against 3 packages.

  • tensorflow
  • tensorflow-cpu (from 2.5.0 up to 2.5.1)
  • tensorflow-gpu (from 2.5.0 up to 2.5.1)

Timeline and source

Published on 6 March 2024 and last revised on 8 July 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from OSV.

References

github.com (Web)
github.com (Web)
nvd.nist.gov (Web)

Details

Severity HIGH
CVSS Score 8.0
CVSS Vector CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CWE CWE-502
Public Exploit ✅ No
Source OSV
Published 2024-03-06
Updated 2026-08-12
Modified 2026-07-08

Affected Packages

Software From version Fixed in
tensorflow — —
tensorflow-cpu 2.5.0 2.5.1
tensorflow-gpu 2.5.0 2.5.1

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