Uninitialized memory access in TensorFlow
Medium4.4CVE-2020-26266 · Published Dec 10, 2020 · updated Jul 8, 2026
### Impact Under certain cases, a saved model can trigger use of uninitialized values during code execution. This is caused by having tensor buffers be filled with the default value of the type but forgetting to [default initialize the quantized floating point types in Eigen](https://github.com/tensorflow/tensorflow/blob/f70160322a579144950dff1537dcbe3c7c09d6f5/third_party/eigen3/unsupported/Eigen/CXX11/src/FixedPoint/FixedPointTypes.h#L61-L104): ```cc struct QUInt8 { QUInt8() {} // ... uint8_t value; }; struct QInt16 { QInt16() {} // ... int16_t value; }; struct QUInt16 { QUInt16() {} // ... uint16_t value; }; struct QInt32 { QInt32() {} // ... int32_t value; }; ``` ### Patches We have patched the issue in GitHub commit [ace0c15a22f7f054abcc1f53eabbcb0a1239a9e2](https://github.com/tensorflow/tensorflow/commit/ace0c15a22f7f054abcc1f53eabbcb0a1239a9e2) and will release TensorFlow 2.4.0 containing the patch. TensorFlow nightly packages after this commit will also have the issue resolved. Since this issue also impacts TF versions before 2.4, we will patch all releases between 1.15 and 2.3 inclusive. ### For more information Please consult [our security g...
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| tensorflow PyPI | < 1.15.5 | 1.15.5 |
| >= 2.0.0, < 2.0.4 | 2.0.4 | |
| >= 2.1.0, < 2.1.3 | 2.1.3 | |
| >= 2.2.0, < 2.2.2 | 2.2.2 | |
| >= 2.3.0, < 2.3.2 | 2.3.2 |
Details and references
### Impact Under certain cases, a saved model can trigger use of uninitialized values during code execution. This is caused by having tensor buffers be filled with the default value of the type but forgetting to [default initialize the quantized floating point types in Eigen](https://github.com/tensorflow/tensorflow/blob/f70160322a579144950dff1537dcbe3c7c09d6f5/third_party/eigen3/unsupported/Eigen/CXX11/src/FixedPoint/FixedPointTypes.h#L61-L104): ```cc struct QUInt8 { QUInt8() {} // ... uint8_t value; }; struct QInt16 { QInt16() {} // ... int16_t value; }; struct QUInt16 { QUInt16() {} // ... uint16_t value; }; struct QInt32 { QInt32() {} // ... int32_t value; }; ``` ### Patches We have patched the issue in GitHub commit [ace0c15a22f7f054abcc1f53eabbcb0a1239a9e2](https://github.com/tensorflow/tensorflow/commit/ace0c15a22f7f054abcc1f53eabbcb0a1239a9e2) and will release TensorFlow 2.4.0 containing the patch. TensorFlow nightly packages after this commit will also have the issue resolved. Since this issue also impacts TF versions before 2.4, we will patch all releases between 1.15 and 2.3 inclusive. ### 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.
- CVSS 3.1
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
- Severity from
- GitHub (reviewed advisory)
- Weakness
- CWE-908
- Also known as
- BIT-tensorflow-2020-26266, CVE-2020-26266, PYSEC-2020-254, PYSEC-2020-297, PYSEC-2020-332
- github.com/tensorflow/tensorflow/security/advisories/GHSA-qhxx-j73r-qpm2
- nvd.nist.gov/vuln/detail/CVE-2020-26266
- github.com/tensorflow/tensorflow/commit/ace0c15a22f7f054abcc1f53eabbcb0a1239a9e2
- github.com/pypa/advisory-database/tree/main/vulns/tensorflow-cpu/PYSEC-2020-297.yaml
- github.com/pypa/advisory-database/tree/main/vulns/tensorflow-gpu/PYSEC-2020-332.yaml
- github.com/pypa/advisory-database/tree/main/vulns/tensorflow/PYSEC-2020-254.yaml
- github.com/tensorflow/tensorflow
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|---|---|---|---|
| Dec 102020 | Heap out of bounds access in MakeEdge in TensorFlow Medium4.4Dec 10, 2020 | Medium4.4 | 1.15.5+4 more |
| Dec 102020 | CHECK-fail in LSTM with zero-length input in TensorFlowMedium4.4Dec 10, 2020 | Medium4.4 | 1.15.5+4 more |
| Dec 102020 | Write to immutable memory region in TensorFlowMedium4.4Dec 10, 2020 | Medium4.4 | 1.15.5+4 more |
| Dec 102020 | Lack of validation in data format attributes in TensorFlowLow4.4Dec 10, 2020 | Low4.4 | 1.15.5+4 more |
| Nov 132020 | Float cast overflow undefined behaviorMedium3.7Nov 13, 2020 | Medium3.7 | 2.4.0 |
| Nov 132020 | Segfault in `tf.quantization.quantize_and_dequantize`High5.9Nov 13, 2020 | High5.9 | 2.4.0 |