The vulnerability allows a repository author to craft a symlink that points outside the checked‑out workspace. The internal template functions readFile, pathExists, isDir, and matchPaths resolve the link naïvely, causing the tool to follow the link and read arbitrary runner‑accessible files. The leaked content is injected into generated configuration and can appear in the Infracost dashboard or a pull‑request comment, potentially exposing secrets when the workflow provides them.

The flaw exists in all Infracost releases prior to v0.10.45. Attackers only need to supply a malformed repository containing a malicious symlink; any user of the affected version running Infracost will be able to read files that the CI runner can access.

The CVSS score of 5.9 indicates moderate severity. EPSS is not available, and the vulnerability is not listed in CISA's KEV catalog, suggesting it has not yet been widely exploited. However, because Infracost is commonly run in CI/CD pipelines, a malicious repository could exercise the flaw during normal job execution. The attack vector is likely local to the CI runner, with the attacker controlling the repository contents.