CVE-2024-32646 | vyper performs double eval of the slice args when buffer from adhoc locations

Vyper is a pythonic Smart Contract Language for the Ethereum virtual machine. In versions 0.3.10 and prior, using the `slice` builtin can result in a double eval vulnerability when the buffer argument is either `msg.data`, `self.code` or `<address>.code` and either the `start` or `length` arguments have side-effects. It can be easily triggered only with the versions `<0.3.4` as `0.3.4` introduced the unique symbol fence. No vulnerable production contracts were found. Additionally, double evaluation of side-effects should be easily discoverable in client tests. As such, the impact is low. As of time of publication, no fixed versions are available.

Published: 2024-04-25 Last update: 2025-01-02 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-32646 is rated Moderate Risk (46.5/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.69%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2024-32646

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-14 0.59% 0.69% +0.10%
2 2025-11-21 0.23% 0.59% +0.36%
3 2025-11-18 — 0.23% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-32646

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]

Weakness enumeration for CVE-2024-32646

GitHub Security Advisory for CVE-2024-32646

GHSA-r56x-j438-vw5m · Severity: medium · Ecosystem: pip — vyper performs double eval of the slice start/length args in certain cases

Affected software / configurations for CVE-2024-32646

Vendor Product Version Raw CPE
vyperlang vyper < 0.4.0 cpe:2.3:a:vyperlang:vyper:*:*:*:*:*:python:*:*

References for CVE-2024-32646

cvelogic Threat Intelligence