Executive brief
Atlantis is a Terraform pull request automation tool that manages infrastructure-as-code deployments. An attacker with repository access or API authentication can inject path traversal sequences into workspace configuration, causing Atlantis to create, modify, or delete directories outside its intended workspace boundaries. This could lead to loss of data, service disruption, or manipulation of the host system's filesystem.
Technical details
The vulnerability is a classic path traversal (CWE-22) caused by insufficient input validation of the workspace parameter before it is joined into filesystem paths. An attacker can supply a workspace value such as "../../../../../../../../tmp/f1-canary" through repository-level atlantis.yaml configuration or via an authenticated /api/plan request. Atlantis then resolves this path and uses it for working-directory operations including os.RemoveAll() and os.MkdirAll() calls, allowing the attacker to create or delete directories outside the intended ~/.atlantis/repos/ hierarchy. The attack requires low privilege (repository access or API authentication) and network access. Terraform eventually rejects the invalid workspace name, but only after Atlantis has already performed the filesystem operations, making the window for exploitation unavoidable. The fix is available in Atlantis 0.45.0.
Affected products
- RunAtlantis Atlantis >= 0.19.8, < 0.45.0
Timeline
- 2026-07-02: disclosed: Vulnerability published to GitHub Advisory Database (CVE-2026-64679)
- 2026-07-02: patched: Fix released in Atlantis 0.45.0
- 2026-08-21: advisory: Advisory reviewed and published to GitHub Advisory Database