Memory corruption in Vyper

published 2021-10-06 5 y ago modified 2026-07-08 4 mo ago also GHSA-xv8x-pr4h-73jv , PYSEC-2021-365 , EUVD-2021-0459

cvss: 7.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.1%; EPSS 1.1% chance of exploitation in 30 days, percentile 65%
public exploits: 0; none known

Vyper is a Pythonic Smart Contract Language for the EVM. In affected versions when performing a function call inside a literal struct, there is a memory corruption issue that occurs because of an incorrect pointer to the the top of the stack. This issue has been resolved in version 0.3.0.

Patch / fix

fixed in 2 links 1

pypi vyper 0.3.0
vyperlang vyper 0.3.0

github.com/vyperlang/vyper#2447 pull request

Exploit prediction

1.07% chance of exploitation in the next 30 days, higher than 65% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.5	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	6.5	AV:N/AC:L/Au:S/C:P/I:P/A:P
GitHub	3.1	7.5	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem	package	affected	fixed in
pypi	vyper	<0.3.0	0.3.0

Affected products

vyperlang vyper

Classification

Weakness

CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

References

github.com /vyperlang/vyper/pull/2447
web, patch, third-party-advisory
github.com /vyperlang/vyper/security/advisories/GHSA-xv8x-pr4h-73jv
web, third-party-advisory, advisory
nvd.nist.gov /vuln/detail/CVE-2021-41121
advisory
github.com /pypa/advisory-database/tree/main/vulns/vyper/PYSEC-2021-365.yaml
web
github.com /vyperlang/vyper
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary