How severe is CVE-2021-41496?

CVE-2021-41496 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-41496 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-41496?

CVE-2021-41496 affects Numpy. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-41496?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-41496 published?

CVE-2021-41496 was published on 2021-12-17 and last updated on 2026-06-17.

CVE-2021-41496

CVE-2021-41496 is a medium-severity vulnerability in Numpy with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-120.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
CVSS v2: 2.1
EPSS exploit prediction: 0% (29th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: Numpy
Published: 2021-12-17
Last modified: 2026-06-17

Description

Buffer overflow in the array_from_pyobj function of fortranobject.c in NumPy < 1.19, which allows attackers to conduct a Denial of Service attacks by carefully constructing an array with negative values. NOTE: The vendor does not agree this is a vulnerability; the negative dimensions can only be created by an already privileged user (or internally)

Frequently asked questions

What is CVE-2021-41496?: Buffer overflow in the array_from_pyobj function of fortranobject.c in NumPy < 1.19, which allows attackers to conduct a Denial of Service attacks by carefully constructing an array with negative values. NOTE: The vendor does not agree this is a vulnerability; the negative dimensions can only be created by an already privileged user (or internally)
How severe is CVE-2021-41496?: CVE-2021-41496 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-41496 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-41496?: CVE-2021-41496 affects Numpy. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-41496?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-41496 published?: CVE-2021-41496 was published on 2021-12-17 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:numpy:numpy:*:*:*:*:*:*:*:*

More vulnerabilities in Numpy

CVE-2019-6446 — Critical (CVSS 9.8): An issue was discovered in NumPy before 1.16.3. It uses the pickle Python module unsafely, which allows remote…
CVE-2017-12852 — High (CVSS 7.5): The numpy.pad function in Numpy 1.13.1 and older versions is missing input validation. An empty list or ndarray will…
CVE-2014-1859 — Medium (CVSS 5.5): (1) core/tests/test_memmap.py, (2) core/tests/test_multiarray.py, (3) f2py/f2py2e.py, and (4) lib/tests/test_io.py in…
CVE-2014-1858 — Medium (CVSS 5.5): __init__.py in f2py in NumPy before 1.8.1 allows local users to write to arbitrary files via a symlink attack on a…
CVE-2021-41495 — Medium (CVSS 5.3): Null Pointer Dereference vulnerability exists in numpy.sort in NumPy &lt and 1.19 in the PyArray_DescrNew function due…
CVE-2021-34141 — Medium (CVSS 5.3): An incomplete string comparison in the numpy.core component in NumPy before 1.22.0 allows attackers to trigger slightly…

All CVEs affecting Numpy →

Other CWE-120 (Classic Buffer Overflow) vulnerabilities

CVE-2025-48611 — Critical (CVSS 10.0): In DeviceId of DeviceId.java, there is a possible desync in persistence due to a missing bounds check. This could lead…
CVE-2026-24823 — Critical (CVSS 10.0): Out-of-bounds Write, Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in FASTSHIFT…
CVE-2026-24810 — Critical (CVSS 10.0): Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in rethinkdb (src/cjson modules).…
CVE-2026-24800 — Critical (CVSS 10.0): Out-of-bounds Write, Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in tildearrow…
CVE-2025-9962 — Critical (CVSS 10.0): A buffer overflow vulnerability in Novakon P series allows attackers to gain root permission without prior…
CVE-2010-10016 — Critical (CVSS 10.0): BS.Player version 2.57 (build 1051) contains a vulnerability in its playlist import functionality. When processing .m3u…

Browse all CWE-120 (Classic Buffer Overflow) vulnerabilities →