Summary
Atlantis Workspace Handling has Path Traversal that Allows Out-of-Bounds Directory Deletion/Creation
Atlantis versions >= 0.19.8 and < 0.45.0 did not consistently validate user-controlled workspace values before using them to construct local workspace paths.
A crafted workspace value containing path traversal segments could cause Atlantis to resolve workspace paths outside the intended per-pull workspace directory. In vulnerable versions or code paths, Atlantis could create, use, or remove/recreate out-of-bounds directories with the privileges of the Atlantis process user, before Terraform rejected the invalid workspace name.
The issue is fixed in Atlantis 0.45.0.
Details
The issue is a path traversal vulnerability in Atlantis workspace handling. workspace values can be supplied through repository-level atlantis.yaml configuration accepted by the server or through authenticated API input. A value such as ../../../../../../../../tmp/f1-canary could escape the intended Atlantis workspace root.
In affected code paths, Atlantis used the resolved workspace path for local working-directory operations. For example, workspace values were joined into repo pull paths, and clone preparation paths could call directory removal/recreation operations such as os.RemoveAll and os.MkdirAll on the resolved directory.
PoC
In a local PoC using repo-level atlantis.yaml, the following workspace value caused Atlantis to resolve and use /tmp/f1-canary outside ~/.atlantis/repos/...:
version: 3
projects:
- dir: .
workspace: ../../../../../../../../tmp/f1-canary
Atlantis logs showed the out-of-bounds directory being created and Terraform being run with /tmp/f1-canary as the working directory. Terraform rejected the workspace name only after Atlantis had already used the out-of-bounds path.
Impact
A user who can cause Atlantis to process a crafted workspace value, for example through repository-level atlantis.yaml configuration accepted by the server or an authenticated /api/plan request, may cause filesystem operations to occur outside the intended workspace boundary.
Depending on the affected version, code path, deployment configuration, and filesystem permissions, this may result in unintended directory creation, deletion, or reuse, integrity impact to writable local paths, or denial of service. Containerized deployments may limit host impact, but writable mounted volumes and persistent Atlantis data paths remain relevant.
Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.
CVE-2026-64679 has a CVSS score of 8.1 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.45.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-64679? CVE-2026-64679 is a high-severity path traversal vulnerability in github.com/runatlantis/atlantis (go), affecting versions >= 0.19.8, < 0.45.0. It is fixed in 0.45.0. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
- How severe is CVE-2026-64679? CVE-2026-64679 has a CVSS score of 8.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of github.com/runatlantis/atlantis are affected by CVE-2026-64679? github.com/runatlantis/atlantis (go) versions >= 0.19.8, < 0.45.0 is affected.
- Is there a fix for CVE-2026-64679? Yes. CVE-2026-64679 is fixed in 0.45.0. Upgrade to this version or later.
- Is CVE-2026-64679 exploitable, and should I be worried? Whether CVE-2026-64679 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-64679 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-64679? Upgrade
github.com/runatlantis/atlantisto 0.45.0 or later.