Which versions of Vyper are affected by CVE-2025-27105?

CVE-2025-27105 is a low-severity vulnerability in vyper involving out-of-bounds write (CVSS 2.3).. A patch is available.

Is there a public PoC exploit available for CVE-2025-27105?

Yes, a public proof-of-concept exploit is available for CVE-2025-27105. Prioritise patching immediately. EPSS: 0.3%.

How to fix or mitigate CVE-2025-27105?

During next maintenance window: Apply vendor patches when convenient. Verify out-of-bounds write controls are in place.

Vyper CVE-2025-27105

Q: What is the CVSS score of CVE-2025-27105?

CVE-2025-27105 has a CVSS 4.0 base score of 2.3 (Low). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/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:X. EPSS exploitation probability: 0.3%.

LOW

Out-of-bounds Write (CWE-787)

2025-02-21 security-advisories@github.com

Memory Corruption Buffer Overflow Vyper

2.3

CVSS 4.0 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

2.3 LOW

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/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:X

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/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:X

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

Analysis Generated

Mar 28, 2026 - 18:27 vuln.today

PoC Detected

Mar 28, 2025 - 20:02 vuln.today

Public exploit code

CVE Published

Feb 21, 2025 - 22:15 nvd

LOW 2.3

Blast Radius

ecosystem impact

† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth

1 pypi packages depend on vyper (1 direct, 0 indirect)

Ecosystem-wide dependent count for version 0.4.1.

DescriptionGitHub Advisory

vyper is a Pythonic Smart Contract Language for the EVM. Vyper handles AugAssign statements by first caching the target location to avoid double evaluation. However, in the case when target is an access to a DynArray and the rhs modifies the array, the cached target will evaluate first, and the bounds check will not be re-evaluated during the write portion of the statement. This issue has been addressed in version 0.4.1 and all users are advised to upgrade. There are no known workarounds for this vulnerability.

AnalysisAI

vyper is a Pythonic Smart Contract Language for the EVM. Rated low severity (CVSS 2.3), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified as Out-of-bounds Write (CWE-787), which allows attackers to write data beyond allocated buffer boundaries leading to code execution or crashes. vyper is a Pythonic Smart Contract Language for the EVM. Vyper handles AugAssign statements by first caching the target location to avoid double evaluation. However, in the case when target is an access to a DynArray and the rhs modifies the array, the cached target will evaluate first, and the bounds check will not be re-evaluated during the write portion of the statement. This issue has been addressed in version 0.4.1 and all users are advised to upgrade. There are no known workarounds for this vulnerability. Affected products include: Vyperlang Vyper. Version information: version 0.4.1.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Validate write boundaries, use memory-safe languages, enable compiler protections (ASLR, stack canaries).