Vulnerability · Published Feb 21, 2025 · Assigned by GitHub_M

CVE-2025-26622sqrt doesn't define rounding behavior in Vyper

High 7.5

In plain English

A high-severity security flaw in vyper from vyperlang. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.3%top 74.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

vyper is a Pythonic Smart Contract Language for the EVM. Vyper `sqrt()` builtin uses the babylonian method to calculate square roots of decimals. Unfortunately, improper handling of the oscillating final states may lead to sqrt incorrectly returning rounded up results. This issue is being addressed and a fix is expected in version 0.4.1. Users are advised to upgrade as soon as the patched release is available. There are no known workarounds for this vulnerability.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	vyper	0.4.1	GHSA-2p94-8669-xg86
PyPI	vyper	0.4.1	PYSEC-2025-29

Affected products (as reported)

Vendor	Product	Versions
vyperlang	vyper	< 0.4.1

Weakness: CWE-682 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

References

https://github.com/vyperlang/vyper/security/advisories/GHSA-2p94-8669-xg86 x_refsource_CONFIRM
https://github.com/vyperlang/vyper/pull/4486 x_refsource_MISC