CVE-2023-30629

Vyper's raw_call with outsize=0 and revert_on_failure=False returns incorrect success value

HIGH
7.5
CVSS Score
Published: April 24, 2023 at 09:58 PM UTC
Updated: June 17, 2026 at 05:55 AM UTC
1 product affected across 1 vendorVyper

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Severity
HIGH7.5
Exploit prediction
EPSS 0.9%
SSVC
No known exploit

Description

Vyper is a Pythonic Smart Contract Language for the ethereum virtual machine. In versions 0.3.1 through 0.3.7, the Vyper compiler generates the wrong bytecode. Any contract that uses the `raw_call` with `revert_on_failure=False` and `max_outsize=0` receives the wrong response from `raw_call`. Depending on the memory garbage, the result can be either `True` or `False`. A patch is available and, as of time of publication, anticipated to be part of Vyper 0.3.8. As a workaround, one may always put `max_outsize>0`.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 0.3.70.3.1 ≤ v < 0.3.8
Affected range stops below 0.3.8, so it looks safe — our inference, not a vendor statement

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-670

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