{"id":"CVE-2018-18920","url":"https://www.cyber-defence.io/tools/cve/CVE-2018-18920","generatedAt":"2026-10-28T20:26:23.777Z","title":"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.","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.\"","published":"2018-11-12T02:29:00.000Z","lastModified":"2026-06-17T01:48:07.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.0","score":8.8,"severity":"HIGH","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"},"cwe":["CWE-119"],"affected":["ethereum/py-evm"],"epss":{"score":0.02926,"percentile":0.86991,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (2.93%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/ethereum/py-evm/issues/1448","tags":["Exploit","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://twitter.com/AlexanderFisher/status/1060923428641878019","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://twitter.com/NettaLab/status/1060889400102383617","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://www.reddit.com/r/ethereum/comments/9vkk2g/netta_labs_claim_to_have_found_a_vulnerability_in/e9d3wyx/","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/ethereum/py-evm/issues/1448","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://twitter.com/AlexanderFisher/status/1060923428641878019","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://twitter.com/NettaLab/status/1060889400102383617","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.reddit.com/r/ethereum/comments/9vkk2g/netta_labs_claim_to_have_found_a_vulnerability_in/e9d3wyx/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2018-18920","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}