CVE-2026-114115

Vyper 0.3.8 through 0.5.0b1 contains a compiler miscompilation vulnerability in parse_IfExp that reads nested arrays with narrower inner bounds using the wider result type's memory layout. When a ternary selects the narrower array, inner arrays after the first are read at wrong offsets, causing contracts to silently store corrupted values or revert.

CVSS 4.0

6.3CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS 3.1

3.7CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS

0.3% chance of exploitation in the next 30 days; higher than 19% of CVEs (scores of 2026-10-25)

CWE

CWE-843

Published

2026-10-21

Modified

2026-10-22

Record from

the NVD, synced 2026-10-23

References

• https://github.com/vyperlang/vyper/commit/1fb7dfe2
• https://github.com/vyperlang/vyper/security/advisories/GHSA-cw3h-xwxq-8cx2
• https://www.vulncheck.com/advisories/vyper-0.3.8-through-0.5-0b1-memory-misread-via-ternary-nested-array-selection

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