Vulnerability · Published Mar 31, 2026 · Assigned by GitHub_M

CVE-2026-34060Ruby LSP has arbitrary code execution through branch setting

Critical 9.8

In plain English

A critical-severity code injection in ruby-lsp from Shopify. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 43% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.8Critical

Exploit odds (30 days)0.5%top 57.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Ruby LSP is an implementation of the language server protocol for Ruby. Prior to Shopify.ruby-lsp version 0.10.2 and ruby-lsp version 0.26.9, the rubyLsp.branch VS Code workspace setting was interpolated without sanitization into a generated Gemfile, allowing arbitrary Ruby code execution when a user opens a project containing a malicious .vscode/settings.json. This issue has been patched in Shopify.ruby-lsp version 0.10.2 and ruby-lsp version 0.26.9.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:14	ruby-ruby-lsp	0.26.9-0.1	DEBIAN-CVE-2026-34060
RubyGems	ruby-lsp	0.26.9	GHSA-c4r5-fxqw-vh93

Affected products (as reported)

Vendor	Product	Versions
Shopify	ruby-lsp	< 0.26.9
Shopify	Shopify.ruby-lsp	< 0.10.2

Weakness: CWE-94 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

https://github.com/Shopify/ruby-lsp/security/advisories/GHSA-c4r5-fxqw-vh93 x_refsource_CONFIRM
https://github.com/Shopify/ruby-lsp/releases/tag/v0.26.9 x_refsource_MISC