LowVulnerability

CVE-2021-29581: TensorFlow denial of service via empty input in CTC beam search decoder

Source: NVD(opens in a new tab)
Identifier: CVE-2021-29581
Published: May 14, 2021
Record updated: October 10, 2026

Affected: tensorflow < 2.1.4, fixed in 2.1.4, released June 15, 2021, 31 days after disclosure
tensorflow >= 2.2.0, < 2.2.3, fixed in 2.2.3, released June 15, 2021, 31 days after disclosure
tensorflow >= 2.3.0, < 2.3.3, fixed in 2.3.3, released June 15, 2021, 31 days after disclosure
and 9 more
Known exploitation: Not listed in the CISA Known Exploited Vulnerabilities catalog at the last check.
EPSS: 0.2%

Summary

CVE-2021-29581 affects TensorFlow's `tf.raw_ops.CTCBeamSearchDecoder`, which lacks input validation. The implementation fails to detect an empty input tensor and reads from a null buffer, so an attacker can trigger a denial of service through segmentation faults.

Mitigation

The fix will be included in TensorFlow 2.5.0. The commit will also be cherrypicked to TensorFlow 2.4.2, TensorFlow 2.3.3, TensorFlow 2.2.3 and TensorFlow 2.1.4.

Details

Scores and exploitation

CVSS score: 2.5(low)
Patch available: Yes
EPSS: 0.2%Estimated probability that this CVE is exploited in the next 30 days, from the FIRST Exploit Prediction Scoring System. Read on November 4, 2026.

Weaknesses and techniques

Weakness (CWE): CWE-908

Affected

Packages: tensorflow@< 2.1.4 (fixed: 2.1.4)
tensorflow@>= 2.2.0, < 2.2.3 (fixed: 2.2.3)
tensorflow@>= 2.3.0, < 2.3.3 (fixed: 2.3.3)
tensorflow@>= 2.4.0, < 2.4.2 (fixed: 2.4.2)
tensorflow-cpu@< 2.1.4 (fixed: 2.1.4)
tensorflow-cpu@>= 2.2.0, < 2.2.3 (fixed: 2.2.3)
tensorflow-cpu@>= 2.3.0, < 2.3.3 (fixed: 2.3.3)
tensorflow-cpu@>= 2.4.0, < 2.4.2 (fixed: 2.4.2)
tensorflow-gpu@< 2.1.4 (fixed: 2.1.4)
tensorflow-gpu@>= 2.2.0, < 2.2.3 (fixed: 2.2.3)
tensorflow-gpu@>= 2.3.0, < 2.3.3 (fixed: 2.3.3)
tensorflow-gpu@>= 2.4.0, < 2.4.2 (fixed: 2.4.2)
Vendors: Google

Classification

Attack type: Denial of service
Attack sophistication: Trivial
AI component targeted: Framework
Impact: Availability
Labels: security

How this record was produced

Summaries, mitigations and labels on this page are generated automatically from the source. The linked source is authoritative. The source gives this advisory a description and no title, so the title above is a headline generated from the source text.

Original source: https://nvd.nist.gov/vuln/detail/CVE-2021-29581

First tracked: February 15, 2026 at 08:39 PM ET, from NVD/CVE Database

Classifier: claude-haiku-5-5, prompt v4

Classifier confidence: 90% (self-assessed)

Affected packages in the Exposure Registry

Matched by package name and ecosystem. Each entry shows whether the package delegates to a language model and how many tracked packages depend on it.

tensorflowPyPINo LLM dependency detected · 26 tracked dependents
tensorflow-gpuPyPINo LLM dependency detected · 2 tracked dependents

Summary

Mitigation

Affected packages in the Exposure Registry

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