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Fencer Vulns
high 7.8

CVE-2021-41219 json

Undefined behavior via `nullptr` reference binding in sparse matrix multiplication

published 2021-11-05 5 y ago modified 2026-09-08 2 mo ago also BIT-tensorflow-2021-41219 , EUVD-2021-0441 , GHSA-4f99-p9c2-3j8x , PYSEC-2021-411 , PYSEC-2021-628 , PYSEC-2021-826

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 11%
public exploits
0
none known

Summary

TensorFlow is an open source platform for machine learning. In affected versions the code for sparse matrix multiplication is vulnerable to undefined behavior via binding a reference to `nullptr`. This occurs whenever the dimensions of `a` or `b` are 0 or less. In the case on one of these is 0, an empty output tensor should be allocated (to conserve the invariant that output tensors are always allocated when the operation is successful) but nothing should be written to it (that is, we should return early from the kernel implementation). Otherwise, attempts to write to this empty tensor would result in heap OOB access. The fix will be included in TensorFlow 2.7.0. We will also cherrypick this commit on TensorFlow 2.6.1, TensorFlow 2.5.2, and TensorFlow 2.4.4, as these are also affected and still in supported range.

Patch / fix

  • pypi tensorflow 2.4.4, 2.5.2, 2.6.1, 2.7.0
  • pypi tensorflow-cpu 2.4.4, 2.5.2, 2.6.1, 2.7.0
  • pypi tensorflow-gpu 2.4.4, 2.5.2, 2.6.1, 2.7.0
  • bitnami tensorflow 2.4.4, 2.5.2, 2.6.1
  • google tensorflow 2.4.4, 2.5.2
  • tensorflow Arch Linux 2.6.1-1

arch linux advisories AVG-2529

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/tensorflow/tensorflow/security/advisories/GHSA-4f99-p9c2-3j8x referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
GitHub 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 4.6 AV:L/AC:L/Au:N/C:P/I:P/A:P
OSV 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
pypi tensorflow
>=2.6.0, <2.6.1
>=2.5.0, <2.5.2
<2.4.4
>=2.7.0rc0, <2.7.0
2.6.1
2.5.2
2.4.4
2.7.0
pypi tensorflow-cpu
>=2.6.0, <2.6.1
>=2.5.0, <2.5.2
<2.4.4
>=2.7.0rc0, <2.7.0
2.6.1
2.5.2
2.4.4
2.7.0
pypi tensorflow-gpu
>=2.6.0, <2.6.1
>=2.5.0, <2.5.2
<2.4.4
>=2.7.0rc0, <2.7.0
2.6.1
2.5.2
2.4.4
2.7.0
bitnami tensorflow
<2.4.4
>=2.5.0, <2.5.2
>=2.6.0, <2.6.1
2.4.4
2.5.2
2.6.1

Affected products

  • tensorflow tensorflow

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.