CVE-2025-21607: Vyper is a Pythonic Smart Contract Language for the EVM

This week

HIGH 7.5REMOTEUPGRADE

CVE-2025-21607 is a high-severity flaw (CVSS 7.5) affecting vyper. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Vyper is a Pythonic Smart Contract Language for the EVM. When the Vyper Compiler uses the precompiles EcRecover (0x1) and Identity (0x4), the success flag of the call is not checked. As a consequence an attacker can provide a specific amount of gas to make these calls fail but let the overall execution continue. Then the execution result can be incorrect. Based on EVM's rules, after the failed precompile the remaining code has only 1/64 of the pr

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 48%)
CISA exploited list	No
Weakness	CWE-670
Published	2025-01-14
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: vyperlang

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-01-14 18:16 UTCPublished CVE record published
2026-06-17 08:43 UTCUpdated Record last modified

vyperlang vyper UPGRADE

Affected: < 0.4.1

Fixed in: 0.4.1

Safe to downgrade to: no unaffected older release

1. Check installed version

pip show vyper

2. UPGRADE to 0.4.1

pip install --upgrade "vyper>=0.4.1"

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-21607?

vyper: upgrade to 0.4.1. Exact commands for each OS are on this page.

Is CVE-2025-21607 being exploited?

CVE-2025-21607 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-21607 affect?

CVE-2025-21607 affects vyper. Severity is high (CVSS 7.5). Vyper is a Pythonic Smart Contract Language for the EVM. When the Vyper Compiler uses the precompiles EcRecover (0x1) and Identity (0x4), the success flag of the call is not checked. As a consequence an attacker can provide a specific amoun

How urgent is CVE-2025-21607?

Priority 49/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2025-27105 CRITICAL 9.1 UPGRADE vyper is a Pythonic Smart Contract Language for the EVM
CVE-2025-27104 HIGH 7.5 UPGRADE vyper is a Pythonic Smart Contract Language for the EVM
CVE-2025-26622 HIGH 7.5 UPGRADE vyper is a Pythonic Smart Contract Language for the EVM
CVE-2024-26149 LOW 3.7 UPGRADE Vyper is a pythonic Smart Contract Language for the ethereum virtual machine
CVE-2024-24567 MEDIUM 4.8 UPGRADE Vyper is a pythonic Smart Contract Language for the ethereum virtual machine

References

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