What is CVE-2025-27105?

CVE-2025-27105 is a critical-severity vulnerability in Vyperlang Vyper, classified under Out-of-bounds Write. CVSS score: 9.1/10. Published 2025-02-21.

How severe is CVE-2025-27105?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Buffer overflow in Vyperlang Vyper

CVE-2025-27105

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.

Vulnerability class: Buffer Overflow

EPSS: 0.006 (44.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.

Affected products

Vyperlang Vyper — versions < 0.4.1

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)

Frequently asked questions

What is CVE-2025-27105?: CVE-2025-27105 is a critical-severity vulnerability in Vyperlang Vyper, classified under Out-of-bounds Write. CVSS score: 9.1/10. Published 2025-02-21.
How severe is CVE-2025-27105?: Critical severity. CVSS v3 base score is 9.1 out of 10.