CVE-2026-42275

Summary
The zrok WebDAV drive backend (davServer.Dir) restricts path traversal through lexical normalization but does not prevent symlink following. When a symbolic link inside the shared DriveRoot points to a location outside that root, remote WebDAV consumers can read files and, on shares without OS-level permission restrictions, write or overwrite files anywhere on the host filesystem accessible to the zrok process.

• Attack Vector: Network, exploitation is performed entirely over the WebDAV endpoint; the attacker issues HTTP requests to the public zrok share URL.
• Attack Complexity: High, a precondition outside the attacker's direct control must hold: a symlink pointing outside DriveRoot must already exist within it (created locally, not via WebDAV).
• Privileges Required: None, zrok share public --backend-mode drive exposes the WebDAV endpoint with no authentication by default.
• User Interaction: None, once the symlink precondition is met, exploitation requires no user interaction.
• Scope: Changed, the vulnerability allows an attacker to escape the WebDAV root (the security boundary) and access the broader host filesystem.
• Confidentiality Impact: High, arbitrary files readable by the zrok process can be retrieved.
• Integrity Impact: High, the WebDAV PUT handler opens files with O_RDWR|O_CREATE|O_TRUNC, meaning symlink targets outside DriveRoot can be overwritten (e.g. ~/.ssh/authorized_keys).
• Availability Impact: None, no direct availability impact.

Affected Components

• drives/davServer/file.go, Dir.OpenFile (line 140), Dir.Stat (line 176), Dir.Mkdir (line 133), Dir.RemoveAll (line 151)
• endpoints/drive/backend.go, NewBackend (line 51–52)

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-2026-42275 has a CVSS score of 8.7 (High). The vector is network-reachable, no 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 (2.0.2); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-42275? CVE-2026-42275 is a high-severity path traversal vulnerability in github.com/openziti/zrok (go), affecting versions <= 1.1.11. It is fixed in 2.0.2. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2026-42275? CVE-2026-42275 has a CVSS score of 8.7 (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.
3. Which packages are affected by CVE-2026-42275?
   • github.com/openziti/zrok (go) (versions <= 1.1.11)
   • github.com/openziti/zrok/v2 (go) (versions < 2.0.2)
4. Is there a fix for CVE-2026-42275? Yes. CVE-2026-42275 is fixed in 2.0.2. Upgrade to this version or later.
5. Is CVE-2026-42275 exploitable, and should I be worried? Whether CVE-2026-42275 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
6. What actually determines whether CVE-2026-42275 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.
7. How do I fix CVE-2026-42275? Upgrade github.com/openziti/zrok/v2 to 2.0.2 or later.