Open WebUI vulnerable to Path Traversal in `POST /api/v1/audio/transcriptions`

published 2026-03-26 7 mo ago modified 2026-07-13 3 mo ago also EUVD-2026-16480 , GHSA-vvxm-vxmr-624h , PYSEC-2026-2764

cvss: 4.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 47%
public exploits: 0; none known

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to version 0.8.6, an unsanitized filename field in the speech-to-text transcription endpoint allows any authenticated non-admin user to trigger a `FileNotFoundError` whose message — including the server's absolute `DATA_DIR` path — is returned verbatim in the HTTP 400 response body, confirming information disclosure on all default deployments. Version 0.8.6 patches the issue.

Patch / fix

fixed in 2 links 1

pypi open-webui 0.8.6
openwebui open_webui 0.8.6

github.com/open-webui/open-webui@387225e commit

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 7 mo ago (2026-03-27)

Exploit prediction

0.57% chance of exploitation in the next 30 days, higher than 47% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/open-webui/open-webui/security/advisories/GHSA-vvxm-vxmr-624h referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
GitHub	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
OSV	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
pypi	open-webui	<0.8.6	0.8.6

Affected products

open-webui open-webui

Classification

Weakness

CWE-22 Improper Limitation of a Pathname to a Restricted Directory
CWE-209 Generation of Error Message Containing Sensitive Information

References

github.com /open-webui/open-webui/commit/387225eb8b3906909436004f84fff1b012e067d4
web
github.com /open-webui/open-webui/security/advisories/GHSA-vvxm-vxmr-624h
exploit, web, vendor-advisory
nvd.nist.gov /vuln/detail/CVE-2026-28786
advisory
github.com /open-webui/open-webui
package
pypi.org /project/open-webui
package
github.com /advisories/GHSA-vvxm-vxmr-624h
advisory

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary