SB2026043029 - Input validation error in Claude Code
Published: April 30, 2026
Security Bulletin ID
SB2026043029
CSH Severity
High
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Input validation error (CVE-ID: CVE-2026-40068)
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to improper input validation in the git worktree commondir trust check when determining folder trust for a crafted repository. A remote attacker can craft a repository with a commondir file pointing to a previously trusted path to execute arbitrary code.
Exploitation requires the victim to clone a malicious repository and run Claude Code within it, and for the attacker to know or guess a path the victim had already trusted.
Remediation
Install update from vendor's website.