CVE-2021-48020

mediumpriority · track · 26EPSS 0.003 · 21 %ileUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.28% (21st) EPSS

CVSS 6.5 · medium

Is it mine?

1 products

Check your exposure

Who says so?

1 sources

osv

EPSS · scored 2026-10-26

Vyper from 0.1.0b4 before 0.3.0 contains a memory corruption vulnerability caused by an incorrect stack tip pointer when internal function calls are performed inside arrays. Contracts placing internal calls in nested array elements, external call arguments, struct literals, or raw_log topics can have memory corrupted, producing incorrect contract behavior.

cvss

Technical severity, 0–10. One row per scoring source.

8.3

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.8–8.3

v3.16.5mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:Lprimary · disclosure@vulncheck.comexploitability 2.2 · impact 4.2

v4.08.3highCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Xsecondary · disclosure@vulncheck.com

v4.04.8mediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Xsecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-787USprimaryCWE-129USCWE-787US

affected products (1)

Products and version ranges known to be affected.

PyPI vyper< 0.2.12osvUSpkg:pypi/vyper

advisories (1)

Vendor and ecosystem advisories describing this.

GHSA-22wc-c9wj-6q2vVVE-2021-0001: Memory corruption using function calls within arrays2021-04-19ghsa · osvUS
### Impact When performing a function call inside an array, there is a memory corruption issue that occurs because of an incorrect pointer to the the tip of the stack. ### Patches This issue was partially fixed in [VVE-2020-0004](https://github.com/vyperlang/vyper/security/advisories/GHSA-2r3x-4mrv-mcxf), however the fix did not update similar code for arrays, which had a similar issue. The issue is fully fixed in https://github.com/vyperlang/vyper/pull/2345

sources

Which sources assert this record, and when.

osv NVD CVE.org MITRE

published 2026-10-21modified 2026-10-22

related (16,096)

Related entries.

ID	severity	EPSS	exploitable	published
CVE-2026-86950US	—OT critical	26.2% (98th)	KEV	2026-09-28
An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 18.7.11 and iPadOS 18.7.11, iOS 26.7.1 and iPadOS 26.7.1, macOS Sequoia 15.8.1,…
CVE-2026-87491US	—OT critical	3.51% (89th)	KEV	2026-09-09
Out of bounds write in V8 in Google Chrome prior to 153.0.8010.36 allowed a remote attacker to execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security…
CVE-2026-53362US	—OT critical	0.71% (53rd)	KEV	2026-07-04
In the Linux kernel, the following vulnerability has been resolved: ipv6: account for fraggap on the paged allocation path In __ip6_append_data(), when the paged-allocation branc…
CVE-2026-53266US	—OT critical	0.93% (61st)	KEV	2026-06-25
In the Linux kernel, the following vulnerability has been resolved: netfilter: bridge: make ebt_snat ARP rewrite writable The ebtables SNAT target keeps the Ethernet source addre…
CVE-2026-11645US	—OT critical	2.44% (84th)	KEV	2026-06-09
Out of bounds read and write in V8 in Google Chrome prior to 149.0.7827.103 allowed a remote attacker to execute arbitrary code inside a sandbox via a crafted HTML page. (Chromium…

+16091 more

references (2) nvd

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan