CVE-2021-41121
Memory corruption in Vyper
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Memory corruption in Vyper
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.
- Record
CVE-2021-41121- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-119
- Updated
- 2026-11-02
EUVDEUVD-2021-0459
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.
- Record
EUVD-2021-0459- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-xv8x-pr4h-73jv
Memory corruption when returning a literal struct with a private call inside of it
Impact
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.
Patches
0.3.0 / #2447
- Record
GHSA-xv8x-pr4h-73jv- CVSS 4.0
- 7.7 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-119
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2021-41121- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.5 Medium
AV:N/AC:L/Au:S/C:P/I:P/A:P - Weakness
- CWE-119
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2021-41121- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVGHSA-xv8x-pr4h-73jv
Memory corruption when returning a literal struct with a private call inside of it
Impact
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.
Patches
0.3.0 / #2447
- Record
GHSA-xv8x-pr4h-73jv- CVSS 4.0
- 7.7 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-119
- Updated
- 2026-11-02
OSVPYSEC-2021-365 No score
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.
- Record
PYSEC-2021-365- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
vyperPyPI |
before 0.3.0 | 0.3.0 |
vyperPyPI |
before 0.3.0, plus listed versions 0.1.0b10.1.0b100.1.0b110.1.0b120.1.0b13 Show 28 moreShow less0.1.0b140.1.0b150.1.0b160.1.0b170.1.0b20.1.0b30.1.0b40.1.0b50.1.0b60.1.0b70.1.0b80.1.0b90.2.10.2.100.2.110.2.120.2.130.2.140.2.150.2.160.2.20.2.30.2.40.2.50.2.60.2.70.2.80.2.9 |
0.3.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-41121 is a high vulnerability (CVSS 7.5) in Vyperlang Vyper, published October 6, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.07%, the 65th percentile. Fixed in vyper 0.3.0.