CVE-2026-64679 is a high-severity (CVSS 8.1) Path Traversal vulnerability in github.com/runatlantis/atlantis. A fix is available for github.com/runatlantis/atlantis — see the affected versions and patch details below.
Atlantis: Path Traversal in Atlantis Workspace Handling Allows Out-of-Bounds Directory Deletion/Creation
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-64679.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-64679 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 384,189 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
github.com/runatlantis/atlantisReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/runatlantis/atlantis | ≥ 0.19.8&&< 0.45.0 | 0.45.0go get github.com/runatlantis/atlantis@v0.45.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/runatlantis/atlantis, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/runatlantis/atlantis to 0.45.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-64679 is resolved across your whole dependency graph.
Workarounds
Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.
Frequently Asked Questions
Is CVE-2026-64679 in your dependencies?
Find it across Go, including transitive dependencies.