CVE-2026-48099

Preconditions

The practical impact depends on the deployment.

The deployment uses a filesystem-backed WsgiDAV share.

The attacker can send WebDAV requests accepted by that share. This may be an anonymous share or an authenticated WebDAV user. This is not an authentication bypass.

Details

The issue is in FilesystemProvider._loc_to_file_path(). The method builds a candidate path with os.path.abspath(os.path.join(root_path, *path_parts)), then checks containment with file_path.startswith(root_path). This is not path-boundary aware. For example, if the configured share root is /tmp/share, a resolved sibling path such as /tmp/share_evil/secret.txt still starts with the string /tmp/share.

In a local proof, this allowed GET, PUT, and DELETE requests to operate on files outside the configured share root.

The WSGI/server layer forwards the encoded dot segment to WsgiDAV's PATH_INFO. The local proof used /%2e%2e/..., which wsgiref passed through as /../....

A sibling or neighboring path exists whose absolute path starts with the configured root path string, such as /tmp/share and /tmp/share_evil.

The WsgiDAV process has OS permissions for the outside path.

WsgiDAV 4.3.3 can allow a WebDAV request path containing an encoded parent-directory segment to escape the configured filesystem share root in a specific path layout.

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-2026-48099 has a CVSS score of 7.1 (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 (4.3.4); upgrading removes the vulnerable code path.

Kodem intelligence

The issue is fixed with version 4.3.4.

1. What is CVE-2026-48099? CVE-2026-48099 is a high-severity path traversal vulnerability in wsgidav (pip), affecting versions <= 4.3.3. It is fixed in 4.3.4. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2026-48099? CVE-2026-48099 has a CVSS score of 7.1 (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.
3. Which versions of wsgidav are affected by CVE-2026-48099? wsgidav (pip) versions <= 4.3.3 is affected.
4. Is there a fix for CVE-2026-48099? Yes. CVE-2026-48099 is fixed in 4.3.4. Upgrade to this version or later.
5. Is CVE-2026-48099 exploitable, and should I be worried? Whether CVE-2026-48099 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-2026-48099 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-2026-48099? Upgrade wsgidav to 4.3.4 or later.