CVE-2021-41495

Exp

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

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

Threat Intelligence & Risk Assessment for CVE-2021-41495

EPSS CVSS CWE GHSA Exploit-DB Affected OS Tracker

Conclusion & alert: CVE-2021-41495 is rated Exploit Available (59.2/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.15%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.05% over the last day, indicating growing attacker interest. Mandatory action: 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-2021-41495

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

Exploit prediction scoring system (EPSS) score for CVE-2021-41495

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	0.11%	1.15%	+1.05%
2	2025-11-21	0.25%	0.11%	-0.15%
3	2025-11-18	—	0.25%	—

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-41495

CVSS metrics for this CVE.

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
5.3	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. 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.	1.6	3.6	[email protected]
3.5	2.0	LOW	`AV:N/AC:M/Au:S/C:N/I:N/A:P` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:M) Exploitation needs some favorable conditions, but not exceptional ones. Authentication (AU:S) A single authentication is required. Confidentiality impact (C:N) No confidentiality impact. Integrity impact (I:N) No integrity impact. Availability impact (A:P) Partial availability impact.	6.8	2.9	[email protected]

Weakness enumeration for CVE-2021-41495

CWE-476 MITRE ↗

GitHub Security Advisory for CVE-2021-41495

GHSA-5545-2q6w-2gh6 · Severity: high · Ecosystem: pip — NumPy NULL Pointer Dereference

OS Trackers for CVE-2021-41495

vendor	priority	summary	link
`debian`	unimportant	CVE-2021-41495 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-2021-41495
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2021-41495
`suse`	medium	—	https://www.suse.com/security/cve/CVE-2021-41495/
`ubuntu`	medium	CVE-2021-41495 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-2021-41495

Affected software / configurations for CVE-2021-41495

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

References for CVE-2021-41495

URL	Tags
https://github.com/numpy/numpy/issues/19038	Exploit Issue Tracking Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.html	Third Party Advisory

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