CVE-2026-71963

Name of the Vulnerable Software and Affected Versions Hermes version 0.21.0

Description An issue exists where coding agents execute git status or git diff for context gathering before trust prompts are presented to the user. If a repository is delivered as files (such as via zip, sync, or USB) rather than through a clone, a malicious .git/config file can be included. By setting the core.fsmonitor variable, an attacker can achieve remote code execution (RCE) on the host machine during the first index refresh, as the subprocess often runs unsandboxed.

Recommendations Update Hermes to a version that includes the fix implemented in commit f6234d0, which utilizes a scrubbed noninteractive git env and the --no-ext-diff/--no-textconv flags on diff paths. As a temporary mitigation, execute git commands using git -c core.fsmonitor=false for every background call.