atlantis: Improper Limitation of a Pathname to a Restricted Directory
CVE-2026-64679 is a high-severity improper limitation of a pathname to a restricted directory vulnerability in atlantis from Runatlantis, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected atlantis versions: >= 0.19.8, < 0.45.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.8% chance of exploitation within 30 days, higher than 57% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of atlantis you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Runatlantis | atlantis | >= 0.19.8, < 0.45.0 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H. Scored by CNA (github.com).
Official description
Atlantis is a self-hosted golang application that listens for Terraform pull request events via webhooks. From 0.19.8 until 0.45.0, Atlantis does not consistently validate user-controlled workspace values supplied through accepted repository-level atlantis.yaml configuration or authenticated /api/plan input before joining them into local workspace paths. Traversal segments can escape the intended per-pull workspace directory and cause clone preparation or other working-directory code paths to call os.RemoveAll, os.MkdirAll, or related filesystem operations on out-of-bounds directories before Terraform rejects the invalid workspace name. This can create, delete, or reuse writable paths with the privileges of the Atlantis process, causing integrity loss or denial of service. This issue is fixed in version 0.45.0.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Limitation of a Pathname to a Restricted Directory
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
How developers prevent this class of flaw
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth.
More Improper Limitation of a Pathname to a Restricted Directory vulnerabilities (CWE-22)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in atlantis
- 8.8 High severity
- 8.0 High severity
- 7.5 High severity
- 9.8 Critical severity
- 7.5 High severity
Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities
- 8.3 High severity
- 7.1 High severity
- 8.8 High severity
- 7.1 High severity
- 7.5 High severity
- 7.0 High severity
Spotted an error? Tell us.