CVE-2026-48099 is a high-severity (CVSS 7.1) Path Traversal vulnerability in wsgidav. A fix is available for wsgidav — see the affected versions and patch details below.
WsgiDAV encoded dot segments can escape filesystem share roots
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-48099 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 394,415 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
wsgidavReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | wsgidav | all versions | 4.3.4pip install --upgrade 'wsgidav==4.3.4' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for wsgidav, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update wsgidav to 4.3.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-48099 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Red Hat products do not ship WsgiDAV. The component is present only in the community python-wsgidav packages for Fedora and EPEL, both of which ship version 4.3.5 — at or above the upstream fixed release 4.3.4 (the vulnerable range is all versions up to and including 4.3.3). The vulnerable code path is therefore not…
No mitigation is required. Red Hat products are not affected by this vulnerability.Source: Red Hat security advisory for CVE-2026-48099 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2026-48099 in your dependencies?
Find it across PyPI, including transitive dependencies.