CVE-2026-48099: Wsgidav WsgiDAV Encoded Dot Segments Can Vulnerability

HIGH
Advisory Identifier: GHSA-wxq4-cc2q-338q
Share
CVSS 7.1
CWE-22
Published
Advisory Summary

CVE-2026-48099 is a HIGH (CVSS 7.1) wsgidav encoded dot segments can vulnerability (CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')) affecting Wsgidav libraries in the PyPI ecosystem. The issue involves wsgidav encoded dot segments can escape filesystem share roots. Remediation is available by upgrading affected packages to version 4.3.4.

CVE-2026-48099 at a Glance

CVE Identifier CVE-2026-48099
GHSA Identifier GHSA-wxq4-cc2q-338q
Severity HIGH
CVSS v3.1 Base Score 7.1
CWE Classification CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Affected Product Wsgidav
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability Low (A:L)

How to Fix CVE-2026-48099

To remediate this vulnerability, upgrade all affected Wsgidav dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

wsgidav fixed: 4.3.4 
pip install wsgidav>=4.3.4
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show wsgidav

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-48099, inspect your installed packages using pip:

pip show wsgidav

Analyze the terminal output to locate any version of Wsgidav in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.3.4), your application is affected.

Note: The pip show wsgidav command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'), where 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. In Wsgidav, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact 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. ### Patches The issue is fixed with version 4.3.4. ### 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.

CVE-2026-48099 Affected Wsgidav Versions

1 component(s)
Fixed Versions:
4.3.4
Product / Package Ecosystem Affected Versions Fixed Version
wsgidav
pypi/wsgidav
PyPI
< 4.3.4
4.3.4

References

GitHub Advisory / Wiki ADVISORY
https://github.com/mar10/wsgidav/security/advisories/GHSA-wxq4-cc2q-338q
Security Fix Commit FIX COMMIT
https://github.com/mar10/wsgidav/commit/f894ed8656d7bdd7438ab8148c5a02546cb15183
Wsgidav Source Repository REPOSITORY
https://github.com/mar10/wsgidav

Frequently Asked Questions

What is CVE-2026-48099?
CVE-2026-48099 is a security vulnerability in Wsgidav involving WsgiDAV encoded dot segments can escape filesystem share roots under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal').
Which Wsgidav versions are affected?
Affected versions include releases prior to 4.3.4 across affected packages: wsgidav.
What version fixes CVE-2026-48099?
Upgrading to 4.3.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is wsgidav affected?
Yes, wsgidav is affected in releases prior to 4.3.4. Upgrade your dependency to 4.3.4 or later.
What is the CVSS score of CVE-2026-48099?
CVE-2026-48099 has a CVSS v3.1 base score of 7.1 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L.
What CWE is associated with CVE-2026-48099?
CVE-2026-48099 is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (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 can I check PyPI dependencies for CVE-2026-48099?
Run the dependency tree command: 'pip show wsgidav'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-wxq4-cc2q-338q",
  "modified" : "2026-06-11T20:28:45Z",
  "published" : "2026-06-11T20:28:45Z",
  "aliases" : [ "CVE-2026-48099" ],
  "summary" : "WsgiDAV encoded dot segments can escape filesystem share roots",
  "details" : "### Impact\nWsgiDAV 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.\n\n### Patches\nThe issue is fixed with version 4.3.4.\n\n### Preconditions\n\nThe practical impact depends on the deployment.\n\nThe deployment uses a filesystem-backed WsgiDAV share.\n\nThe 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.\n\n### Details\n\nThe 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`.\n\nIn a local proof, this allowed GET, PUT, and DELETE requests to operate on files outside the configured share root.\n\nThe WSGI/server layer forwards the encoded dot segment to WsgiDAV's PATH_INFO. The local proof used `/%2e%2e/...`, which wsgiref passed through as `/../...`.\n\nA sibling or neighboring path exists whose absolute path starts with the configured root path string, such as `/tmp/share` and `/tmp/share_evil`.\n\nThe WsgiDAV process has OS permissions for the outside path.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "wsgidav"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "4.3.4"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 4.3.3"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/mar10/wsgidav/security/advisories/GHSA-wxq4-cc2q-338q"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mar10/wsgidav/commit/f894ed8656d7bdd7438ab8148c5a02546cb15183"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/mar10/wsgidav"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-11T20:28:45Z",
    "nvd_published_at" : null
  }
}