CVE-2020-26270: CHECK-fail in LSTM with zero-length input in TensorFlow

Severity: low (CVSS 3.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-12-10 · updated 2026-06-17
Weakness: CWE-20

Description

In affected versions of TensorFlow 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. This is fixed in versions 1.15.5, 2.0.4, 2.1.3, 2.2.2, 2.3.2, and 2.4.0.

Affected products

tensorflow: before 1.15.5; from 2.0.0 before 2.0.4; from 2.1.0 before 2.1.3; from 2.2.0 before 2.2.2; from 2.3.0 before 2.3.2 — fixed in 1.15.5, 2.0.4, 2.1.3, 2.2.2, 2.3.2

How to fix

Upgrade to a fixed version: tensorflow 1.15.5, 2.0.4, 2.1.3, 2.2.2. Check the vendor advisory for mitigations.

References

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