Py-EVM v0.2.0-alpha.33 allows attackers to make a vm.execute_bytecode call that triggers…
Priority MEDIUM 43CWE-119Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA and GitHub. Impact type from CWE-119 and the CVSS impact.
Summary
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."
Why it matters now
EPSS 0.02926 87th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
| — | py-evm (PyPI) | up to 0.2.0a33 | — | No fix listed | GHSA-vqgp-4jgj-5j64 |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
- py-evm (PyPI) Vendor— Affected up to 0.2.0a33 Fixed in — No fix listed GHSA-vqgp-4jgj-5j64
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2018-18920
- 2026-10-03 Alias added: GHSA-vqgp-4jgj-5j64
References
Advisory 5
- https://twitter.com/AlexanderFisher/status/1060923428641878019
- https://twitter.com/NettaLab/status/1060889400102383617
- https://www.reddit.com/r/ethereum/comments/9vkk2g/netta_labs_claim_to_have_found_a_vulnerability_in/e9d3wyx/
- https://nvd.nist.gov/vuln/detail/CVE-2018-18920
- https://github.com/advisories/GHSA-vqgp-4jgj-5j64
Other 4
- https://github.com/ethereum/py-evm
- https://github.com/pypa/advisory-database/tree/main/vulns/evm-py/PYSEC-2018-155.yaml
- https://github.com/pypa/advisory-database/tree/main/vulns/py-evm/PYSEC-2018-96.yaml
- https://www.reddit.com/r/ethereum/comments/9vkk2g/netta_labs_claim_to_have_found_a_vulnerability_in/e9d3wyx
Sources
- CVE-2018-18920 · CVE Program
- CVE-2018-18920 · NVD
- FIRST EPSS
- GHSA-vqgp-4jgj-5j64 · GitHub Advisory Database · CC BY 4.0
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