TI-2026-79162 Aliases CVE-2026-114663 GHSA-9r8w-599f-g6jq

Name shadowing in Vyper miscompiles imported constants and defaults

LOW 38CWE-706Published 2026-10-22 · Updated 2026-10-23

Key facts

Attack vector: Local
Privileges required: None
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: —
Confidentiality · integrity · availability: High · High · High
Fix status: No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

Vyper 0.4.0b1 through 0.5.0b1 miscompiles unfoldable constants and omitted default arguments imported from modules. The compiler resolves their names in the calling function's scope instead of at declaration (CWE-706). When a contract's parameter, local or loop variable shares such a name, attacker-influenced input can replace the intended value, including out-of-range values for narrow types such as uint8, which can corrupt validation or accounting logic.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

Vyper 0.4.0b1 through 0.5.0b1 miscompiles unfoldable constants and omitted default arguments from imported modules, because parse_Name resolves their names in the using function's scope rather than at declaration. When a contract's parameter, local, or loop variable shares such a name, attacker-influenced input can replace the intended value, including out-of-range values for narrow types such as uint8, corrupting validation or accounting logic.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00176 7th percentileScored 2026-11-07

Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
vyperlang	vyper	0.4.0b1 – 0.5.0b1	—	No fix listed	CNA

vyper Vendorvyperlang Affected 0.4.0b1 – 0.5.0b1 Fixed in — No fix listed CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:a:vyperlang:vyper::::::::	—	—	vyperlang

cpe:2.3:a:vyperlang:vyper:*:*:*:*:*:*:*:* Versions — — ·vyperlang

Remediation

The sources list no fixed version for Vyper.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product

Red Hat

Timeline

2026-10-22 Threatist record created from CVE-2026-114663
2026-10-22 Alias added: GHSA-9r8w-599f-g6jq
2026-10-23 Affected versions changed · Red Hat
2026-10-23 CVSS score added · Red Hat
2026-10-23 Priority changed: MEDIUM → LOW
2026-10-23 CISA SSVC decision points changed

References

Advisory 1

GitHub Security Advisory (GHSA-2489-32vh-8rrc)

TI-2024-16182 Vyper bounds check on built-in `slice()` function can be overflowed CVSS 3.1CRITICAL 9.8
TI-2024-14992 concat built-in can corrupt memory in vyper CVSS 3.1CRITICAL 9.8
TI-2024-16184 Vyper array negative index vulnerability CVSS 3.1CRITICAL 9.8
TI-2022-08657 Integer bounds error in Vyper CVSS 3.1CRITICAL 9.8
TI-2022-11796 Multiple evaluation of contract address in call in vyper CVSS 3.1HIGH 8.2
TI-2026-78730 Optimizer miscompilation of msg.value | K in Vyper ternary branches CVSS 4.0HIGH 8.2

See all 52 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences