Open WebUI: Improper Authorization in Standard Channels Allows Message Updates with Read Permission

published 2026-05-11 5 mo ago modified 2026-07-13 3 mo ago also GHSA-jgj3-r8hr-9pjw , PYSEC-2026-2739 , EUVD-2026-30655

cvss: 6.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 20%
public exploits: 0; none known

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.8.6, in standard channels (i.e., channels whose channel.type is neither group nor dm), the endpoint POST /api/v1/channels/{channel_id}/messages/{message_id}/update can be accessed with read permission only. When access_control is set to None, the authorization check has_access(..., type="read") evaluates to True, allowing users who are not the message owner to update messages. As a result, unauthorized modification of other users’ messages is possible. This vulnerability is fixed in 0.8.6.

Patch / fix

fixed in 2

pypi open-webui 0.8.6
openwebui open_webui 0.8.6

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 5 mo ago (2026-05-15)

Exploit prediction

0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/open-webui/open-webui/security/advisories/GHSA-jgj3-r8hr-9pjw referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
OSV	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
GitHub	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/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-862 Missing Authorization

References

github.com /open-webui/open-webui/security/advisories/GHSA-jgj3-r8hr-9pjw
exploit, web, mitigation, vendor-advisory
nvd.nist.gov /vuln/detail/CVE-2026-44571
advisory
github.com /open-webui/open-webui
package
pypi.org /project/open-webui
package
github.com /advisories/GHSA-jgj3-r8hr-9pjw
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.

Summary