This vulnerability arises from the Repomix MCP server's attach_packed_output and read_repomix_output flow, which can register and read arbitrary local .json, .txt, .md, or .xml files without the file_system_read_file runSecretLint() safety check or Repomix packed-output validation, allowing MCP callers to bypass the local file‑read secret‑scanning boundary. Because the file‑system read check and packed‑output validation are bypassed, secret‑scanning of local files is circumvented, enabling an attacker to read sensitive files that may contain credentials or other secrets. The weakness is a CWE-200 information exposure flaw.

The affected product is Repomix from vendor Yamadashy. All releases prior to version 1.14.1 are vulnerable. Users operating Repomix 1.x or earlier must upgrade to 1.14.1 or later to remediate the flaw.

The CVSS score is 6.8, indicating a medium severity. The EPSS score of less than 1% suggests a very low probability of exploitation at the time of analysis. The vulnerability is not listed in the CISA KEV catalog. Attacks would require the ability to invoke the attach_packed_output or read_repomix_output endpoints, so it is inferred that an attacker with API or internal access could exploit it. When successfully exploited, the attacker could read arbitrary local files, potentially exposing secrets and compromising confidentiality.