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TI-2026-78730 Aliases CVE-2026-114117

Optimizer miscompilation of msg.value | K in Vyper ternary branches

Priority HIGH 69CWE-682Published · Updated

Key facts

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

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

Summary

Vyper versions 0.3.8 through 0.5.0b1 contain an optimizer miscompilation (CWE-682) that compiles (msg.value | K) or (len(msg.data) | K), where K is any nonzero integer literal, to the constant 1 when used as a ternary expression branch under -O gas or -O codesize. Affected contracts use the wrong value without warning or revert, which can record deposits incorrectly and lock funds.

Written with Claude Haiku 5.5 from the sources below · 2026-11-03

Description from the CNA

Vyper 0.3.8 through 0.5.0b1 contains an optimizer miscompilation in which (msg.value | K) or (len(msg.data) | K), where K is any nonzero integer literal, is compiled to the constant 1 when used as a ternary expression branch under -O gas (the default) or -O codesize. Affected contracts use the wrong value in storage writes, arithmetic, indexes, return values, or events without warning or revert, which can record deposits incorrectly and lock funds.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00294 22nd 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
Poc
Automatable
No
Technical impact
Partial

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

Affected products

VendorProductAffected versionsFixed inStatusSource
vyperlangvyper0.3.8 – 0.5.0b1—No fix listedCNA
  • vyper Vendorvyperlang Affected 0.3.8 – 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.

CPEVersionsRoleVendor
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 · 2026-11-03

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-21 Threatist record created from CVE-2026-114117
  2. 2026-10-21 CISA SSVC decision points changed
  3. 2026-10-21 Priority changed: MEDIUM → HIGH
  4. 2026-11-03 Affected versions changed · Red Hat
  5. 2026-11-03 CVSS score added · Red Hat

References

Advisory 1

  • 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-2024-21531 vyper performs double eval of the argument of sqrt CVSS 3.1MEDIUM 5.3
See all 52 →

Sources

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