Open WebUI: Stale Admin Role in Socket.IO Session Pool Enables Post-Demotion Cross-User Note Access

published 2026-05-08 6 mo ago modified 2026-07-13 3 mo ago also GHSA-45m8-cpm2-3v65 , PYSEC-2026-2697 , EUVD-2026-30615

cvss: 8.1; 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 0.9.0, administrative role changes and user deletions do not iterate SESSION_POOL to disconnect affected sessions. As a result, a user whose admin role has been revoked retains admin privileges within their existing Socket.IO session for as long as they keep the connection alive (via automatic heartbeats). The gap is exclusive to the Socket.IO session cache. This vulnerability is fixed in 0.9.0.

Patch / fix

fixed in 2

pypi open-webui 0.9.0
openwebui open_webui 0.9.0

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 5 mo ago (2026-05-19)

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-45m8-cpm2-3v65 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.1	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
GitHub	3.1	8.1	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
OSV	3.1	8.1	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Affected packages

ecosystem	package	affected	fixed in
pypi	open-webui	<0.9.0	0.9.0

Affected products

open-webui open-webui

Classification

Weakness

CWE-613 DEPRECATED: Insufficient Session Expiration
CWE-384 Session Fixation
CWE-863 Incorrect Authorization

References

github.com /open-webui/open-webui/security/advisories/GHSA-45m8-cpm2-3v65
web, exploit, vendor-advisory
nvd.nist.gov /vuln/detail/CVE-2026-44553
advisory
github.com /open-webui/open-webui
package
pypi.org /project/open-webui
package
github.com /advisories/GHSA-45m8-cpm2-3v65
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