CVE-2021-41496

Exp

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)

Published: 2021-12-17 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-41496 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.37%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-41496

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-41496

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.03% 0.37% +0.34%
2 2025-11-21 0.05% 0.03% -0.02%
3 2025-11-18 — 0.05% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-41496

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]
2.1 2.0 LOW
AV:L/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 3.9 2.9 [email protected]

Weakness enumeration for CVE-2021-41496

GitHub Security Advisory for CVE-2021-41496

GHSA-f7c7-j99h-c22f · Severity: medium · Ecosystem: pip — Buffer Copy without Checking Size of Input in NumPy

OS Trackers for CVE-2021-41496

vendor priority summary link
debian unimportant CVE-2021-41496 unimportant priority: Debian including 1 source packages (numpy), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 5. https://security-tracker.debian.org/tracker/CVE-2021-41496
redhat medium — https://access.redhat.com/security/cve/CVE-2021-41496
suse medium CVE-2021-41496 severity moderate: SUSE including 289 source package names (1.1.1.0.1.5.568:python3-numpy-1.17.3-10.1, 1.2.0.0.1.5.583:python3-numpy-1.17.3-10.1, …), 455 product×package rows across 50 product lines (Container ses/6/cephcsi/cephcsi, Container ses/6/rook/ceph, … (50 product lines)): Known Affected 231, Fixed 221, Known Not Affected 2, Will Not Fix 1. https://www.suse.com/security/cve/CVE-2021-41496/
ubuntu medium CVE-2021-41496 medium priority: Ubuntu including 1 source packages (numpy), 9 status rows across 9 suites (focal, hirsute, impish, jammy, kinetic, lunar, trusty, upstream, xenial): ignored 4, released 4, not-affected 1. https://ubuntu.com/security/CVE-2021-41496

Affected software / configurations for CVE-2021-41496

Vendor Product Version Raw CPE
numpy numpy < 1.19.0 cpe:2.3:a:numpy:numpy:*:*:*:*:*:*:*:*

References for CVE-2021-41496

URL Tags
https://github.com/numpy/numpy/issues/19000 Exploit Issue Tracking Patch Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.html Third Party Advisory
cvelogic Threat Intelligence