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No exploitation reportedFix available

CVE-2021-41495

No exploitation reported by the sources we read.

  • Published2021-12-17
  • Fixed in1.19.1 · 1.19
  • WeaknessCWE-476

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Null Pointer Dereference vulnerability exists in numpy.sort in NumPy &lt and 1.19 in the PyArray_DescrNew function due to missing return-value validation, which allows attackers to conduct DoS attacks by repetitively creating sort arrays. NOTE: While correct that validation is missing, an error can only occur due to an exhaustion of memory. If the user can exhaust memory, they are already privileged. Further, it should be practically impossible to construct an attack which can target the memory exhaustion to occur at exactly this place

Timeline

dates in UTC
  1. 2021-12-1720:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-41495?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-41495?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

OSV · NVD
numpy
BranchAffectedFixed in
1.19< 1.19.11.19.1
1.19< 1.191.19
Numpy
BranchAffectedFixed in
1.19≤ 1.19.0no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • CVE-2021-41495 Red Hat Product Security18 products fixed · 27 known affected

    numpy: NULL pointer dereference in numpy.sort in in the PyArray_DescrNew() due to missing return-value validation

    numpy-f2py as a component of Red Hat Enterprise Linux 6 · numpy.src as a component of Red Hat Enterprise Linux 6 · numpy-f2py as a component of Red Hat Enterprise Linux 7 · +24 more

  • RHSA-2022:8861 Red Hat Product Security9 products fixed

    Red Hat Security Advisory: Red Hat OpenStack Platform 16.1.9 (numpy) security update

  • RHSA-2022:8852 Red Hat Product Security9 products fixed

    Red Hat Security Advisory: Red Hat OpenStack Platform 16.2.4 (numpy) security update

Full record on NVD

Fix

  1. Update numpy to 1.19.1 · 1.19
  2. Vendor fix Red Hat Product Security RHSA-2022:8861 · 27 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
  3. No fix planned, says the vendor Red Hat Product Security CVE-2021-41495 · 6 productsOut of support scope
  4. No fix planned, says the vendor Red Hat Product Security CVE-2021-41495 · 21 productsWill not fix

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • NVDCVSS 3.15.3read 2026-10-23
  • NVDCVSS 2.03.5read 2026-10-23
  • NVDweakness (CWE)CWE-476read 2026-10-23
  • FIRST EPSSEPSS score1.2 %2026-10-23
  • OSVaffected packages—

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Published
2021-12-17
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2021-41495?

Null Pointer Dereference vulnerability exists in numpy.sort in NumPy &lt and 1.19 in the PyArray_DescrNew function due to missing return-value validation, which allows attackers to conduct DoS attacks by repetitively creating sort arrays. NOTE: While correct that validation is missing, an error can only occur due to an exhaustion of memory. If the user can exhaust memory, they are already privileged. Further, it should be practically impossible to construct an attack which can target the memory exhaustion to occur at exactly this place

Is CVE-2021-41495 actively exploited?

Active exploitation of CVE-2021-41495 has not been confirmed. Its EPSS score was 1.2% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-41495?

CVE-2021-41495 has a CVSS v3 base score of 5.3 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H.

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