CVE-2026-54014

Open WebUI: Sibling-Prefix Path Traversal via /cache/{path} in open-webui/open-webui

Published Jun 23, 2026 CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed

Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6, a path traversal vulnerability exists in open-webui's cache file serving endpoint that allows any authenticated user to read files from sibling directories outside the intended cache directory, by exploiting an incomplete startswith containment check that lacks a trailing path separator. The root cause is that serve_cache_file() in open_webui/main.py validates the resolved path with file_path.startswith(os.path.abspath(CACHE_DIR)) — without appending os.sep. This allows any path resolving to a sibling directory whose name begins with cache (e.g. cache_sibling, cache_backup, cached_models) to pass validation. This vulnerability is fixed in 0.9.6.

Analysis

Technical impact

Open WebUI is a self-hosted AI platform that operates entirely offline. Prior to version 0.9.6, the cache file serving endpoint contains a path traversal flaw. The root cause is an incomplete startswith containment check that omits a trailing path separator when comparing the resolved file path to the absolute CACHE_DIR path. As a result, any authenticated user can request files from sibling directories whose names begin with "cache" (for example, cache_sibling, cache_backup, cached_models), because the check mistakenly deems those paths valid. This allows the reading of arbitrary files, thereby compromising confidentiality. The flaw is classified as CWE‑22 and was fixed in release 0.9.6.

Affected Systems

Open WebUI platforms running versions earlier than 0.9.6 are affected. The vulnerability exists in the open-webui/open-webui product as implemented before the 0.9.6 release. Users of Open WebUI 0.9.6 or later are not impacted.

Risk and Exploitability

The CVSS score of 4.3 indicates medium severity. No EPSS score is available, so the current exploitation probability cannot be quantified, and the vulnerability is not listed in the CISA KEV catalog. Attackers must be authenticated to exploit the flaw, but the code path allows reading arbitrary files within sibling directories. The incomplete validation provides a straightforward exploitation path once the user is logged in, making it a potentially useful tool for attackers who can gain initial user access.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

open-webui

affected

Version	Status	Constraints
`< 0.9.6`	affected	—

Configuration 1 [-]

cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*

No data.

Vendor Product Versions

Open-webui

Version	Status	Scheme	Platform
`[0,0.9.6)`	affected	semver	—

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Upgrade Open WebUI to version 0.9.6 or later, where the path traversal check has been corrected with an appended path separator.
Verify that authentication is properly enforced for the cache endpoint to limit exposure in case further patches are applied.
Consider removing or renaming any sibling directories that begin with "cache" to eliminate the naming pattern that the vulnerability exploits, as an interim mitigation until the patch is applied.

Generated by OpenCVE AI on June 24, 2026 at 10:55 UTC.

Tracking

Advisories

Source	ID	Title
Github GHSA	GHSA-j2c8-v969-8r5c	Open WebUI: Sibling-Prefix Path Traversal via /cache/{path}

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact Low

Integrity Impact None

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.361% probability within 30 days)

Exploitation poc

Automatable no

Technical Impact partial

References

Link	Providers
https://github.com/open-webui/open-webui/security/advisories/GHSA-j2c8-v969-8r5c

History

Jun 24, 2026 2:30 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Jun 23, 2026 8:15 PM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Open-webui Open-webui open-webui
Vendors & Products		Open-webui Open-webui open-webui

Jun 23, 2026 5:30 PM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6, a path traversal vulnerability exists in open-webui's cache file serving endpoint that allows any authenticated user to read files from sibling directories outside the intended cache directory, by exploiting an incomplete startswith containment check that lacks a trailing path separator. The root cause is that serve_cache_file() in open_webui/main.py validates the resolved path with file_path.startswith(os.path.abspath(CACHE_DIR)) — without appending os.sep. This allows any path resolving to a sibling directory whose name begins with cache (e.g. cache_sibling, cache_backup, cached_models) to pass validation. This vulnerability is fixed in 0.9.6.
Title		Open WebUI: Sibling-Prefix Path Traversal via /cache/{path} in open-webui/open-webui
Weaknesses		CWE-22
References		https://github.com/open-webui/open-webui/security/advisories/GHSA-j2c8-v969-8r5c
Metrics		cvssV3_1 `{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'}`