VulnerabilityModified

CVE-2018-18920

HIGH 8.8EPSS 2.93%

Does this matter?

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.

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."

CVSS 3.0: 8.8 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS: 2.93% probability · 87th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-119
Affected: ethereum/py-evm
Source: cve@mitre.org

EPSS trend

EPSS 2.9% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

https://github.com/ethereum/py-evm/issues/1448Exploit, Third Party Advisory
https://twitter.com/AlexanderFisher/status/1060923428641878019Third Party Advisory
https://twitter.com/NettaLab/status/1060889400102383617Third Party Advisory
https://www.reddit.com/r/ethereum/comments/9vkk2g/netta_labs_claim_to_have_found_a_vulnerability_in/e9d3wyx/Third Party Advisory
https://github.com/ethereum/py-evm/issues/1448Exploit, Third Party Advisory
https://twitter.com/AlexanderFisher/status/1060923428641878019Third Party Advisory
https://twitter.com/NettaLab/status/1060889400102383617Third Party Advisory
https://www.reddit.com/r/ethereum/comments/9vkk2g/netta_labs_claim_to_have_found_a_vulnerability_in/e9d3wyx/Third Party Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.