CVE-2018-18920
CVSS v3
8.8
HIGH
EPSS Score
2.9 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
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."
Technical details
- Published
- 2018-11-12
Frequently asked questions
What is CVE-2018-18920?
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."
Is CVE-2018-18920 actively exploited?
Active exploitation of CVE-2018-18920 has not been confirmed. Its EPSS score was 2.9% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2018-18920?
CVE-2018-18920 has a CVSS v3 base score of 8.8 (HIGH severity).
Is CVE-2018-18920 affecting your environment?
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