CHECK-fail in LSTM with zero-length input in TensorFlow
Medium4.4CVE-2020-26270 · Published Dec 10, 2020 · updated Jul 8, 2026
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 Running an LSTM/GRU model where the LSTM/GRU layer receives an input with zero-length results in a `CHECK` failure when using the CUDA backend. This can result in a query-of-death vulnerability, via denial of service, if users can control the input to the layer. ### Patches We have patched the issue in GitHub commit [14755416e364f17fb1870882fa778c7fec7f16e3](https://github.com/tensorflow/tensorflow/commit/14755416e364f17fb1870882fa778c7fec7f16e3) 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-20
- Also known as
- BIT-tensorflow-2020-26270, CVE-2020-26270, PYSEC-2020-256, PYSEC-2020-301, PYSEC-2020-336
- github.com/tensorflow/tensorflow/security/advisories/GHSA-m648-33qf-v3gp
- nvd.nist.gov/vuln/detail/CVE-2020-26270
- github.com/tensorflow/tensorflow/commit/14755416e364f17fb1870882fa778c7fec7f16e3
- github.com/pypa/advisory-database/tree/main/vulns/tensorflow-cpu/PYSEC-2020-301.yaml
- github.com/pypa/advisory-database/tree/main/vulns/tensorflow-gpu/PYSEC-2020-336.yaml
- github.com/pypa/advisory-database/tree/main/vulns/tensorflow/PYSEC-2020-256.yaml
- github.com/tensorflow/tensorflow
More TensorFlow advisories
All TensorFlow| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Dec 102020 | Uninitialized memory access in TensorFlow CVE-2020-26266Medium4.4fixed in 1.15.5, 2.0.4, 2.1.3, 2.2.2 | Medium4.4 | 1.15.5, 2.0.4, 2.1.3, 2.2.2 |
| Dec 102020 | Lack of validation in data format attributes in TensorFlow CVE-2020-26267Low4.4fixed in 1.15.5, 2.0.4, 2.1.3, 2.2.2 | Low4.4 | 1.15.5, 2.0.4, 2.1.3, 2.2.2 |
| Dec 102020 | Write to immutable memory region in TensorFlow CVE-2020-26268Medium4.4fixed in 1.15.5, 2.0.4, 2.1.3, 2.2.2 | Medium4.4 | 1.15.5, 2.0.4, 2.1.3, 2.2.2 |
| Dec 102020 | Heap out of bounds access in MakeEdge in TensorFlow CVE-2020-26271Medium4.4fixed in 1.15.5, 2.0.4, 2.1.3, 2.2.2 | Medium4.4 | 1.15.5, 2.0.4, 2.1.3, 2.2.2 |
| Nov 132020 | Float cast overflow undefined behavior CVE-2020-15266Medium3.7fixed in 2.4.0 | Medium3.7 | 2.4.0 |
| Nov 132020 | Segfault in `tf.quantization.quantize_and_dequantize` CVE-2020-15265High5.9fixed in 2.4.0 | High5.9 | 2.4.0 |