CVE-2018-18920

HIGH

Py-EVM v0.2.0-alpha.33 allows attackers to make a vm.execute_bytecode call that triggers computation._stack.values with '"stack": [100, 100, 0]' where b'\x' was expected, resulting in an execution ...

Affects 1 product across 1 vendor.

CVSS 3.08.8
EPSS2.9%
Percentile87th
PatchUnknown
CVSS Vector — Plain English Remotely exploitable over the network, low complexity, no authentication required, requires user interaction, impact contained to the vulnerable component, full confidentiality impact, full integrity impact, full availability impact.
CWE Weakness Definitions
CWE-119: Improper Restriction of Operations within Memory Buffer

Parent class for buffer-related vulnerabilities where operations exceed buffer boundaries.

Related Attack Patterns (CAPEC)
CAPEC-8 Buffer Overflow in an API Call
via CWE-119
CAPEC-9 Buffer Overflow in Local Command-Line Utilities
via CWE-119
CAPEC-10 Buffer Overflow via Environment Variables
via CWE-119
CAPEC-14 Client-side Injection-induced Buffer Overflow
via CWE-119
CAPEC-24 Filter Failure through Buffer Overflow
via CWE-119
Show all 12

Mapping is CWE-to-CAPEC per MITRE CAPEC 3.9.

◆ AI Analysis — automated analysis, not human-reviewed

This vulnerability was disclosed in 2018. A high severity vulnerability affects Ethereum systems (CVE-2018-18920). No public exploit code is currently available. Isolate affected systems if patching is not feasible.

BSID: BS-2018-GLOBAL-127338-H • Model: rule-based-v1 • Confidence: MEDIUM

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Frequently Asked Questions
What is CVE-2018-18920?
This vulnerability was disclosed in 2018. A high severity vulnerability affects Ethereum systems (CVE-2018-18920). No public exploit code is currently available. Isolate affected systems if patching is not feasible.
What is the CVSS score for CVE-2018-18920?
CVE-2018-18920 has CVSS 8.8 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. EPSS: 2.9%.
Is CVE-2018-18920 actively exploited?
No confirmed active exploitation of CVE-2018-18920 as of 2026-05-30.
How do I remediate CVE-2018-18920?
Priority: MEDIUM.
What systems are affected by CVE-2018-18920?
CVE-2018-18920 affects Ethereum Py-Evm.
Vulnerability Details
CVE IDCVE-2018-18920
BSIDBS-2018-GLOBAL-127338-H BreachSpider Global ID
CVSS VectorCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Published2018-11-12
Last Modified2024-11-21
ICS Relevance15%
Weakness (CWE)
Improper Restriction of Operations within Memory Buffer
SourceNVD
Official Description

Py-EVM v0.2.0-alpha.33 allows attackers to make a vm.execute_bytecode call that triggers computation._stack.values with '"stack": [100, 100, 0]' where b'\x' was expected, resulting in an execution failure because of an invalid opcode. This is reportedly related to "smart contracts can be executed indefinitely without gas being paid."

Source: NIST NVD / MITRE CVE Database

Attack Vector Analysis — CITED Relevance

Vulnerability details: Py-EVM v0.2.0-alpha.33 allows attackers to make a vm.execute_bytecode call that triggers computation._stack.values with '"stack": [100, 100, 0]' where b'\x' was expected, resulting in an execution failure because of an invalid opcode. This is reportedly related to "smart contracts can be executed indefinitely without gas being paid." CVSS vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Exploitation Likelihood: MINIMAL

Affected Products
VendorProductAffected Versions
Ethereum Py-Evm 0.2.0
Remediation

No official vendor advisory link on record. See the CVE record →

Threat Intelligence
● Threat Intelligence Validated: October 2026 | Threat Age: 2895 Days
CISA known-exploitedNot in KEV catalog
Public ExploitNot confirmed
PoC CodeNot confirmed
AI Enrichment Record — provenance & audit hash
Modelrule-based-v1
ConfidenceMEDIUM
Enriched At2026-05-24
SHA-512 Audit Hash6cd8fadaca8270b17abd92ad9e26cc5a1b59ac87431c49bf5a38a91ec7d2dc35f427759e905da210596195fc1a1a5557af813701b2b7b5157364a5271c641c39
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