open-webui Open WebUI up to 0.9.2 Excel-preview XLSX.utils.sheet_to_html cross site scripting

CVSS Meta Temp Score
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CTI Interest Score
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4.4$0-$5k0.00

Summaryinfo

A vulnerability classified as problematic has been found in open-webui Open WebUI up to 0.9.2. This vulnerability affects unknown code of the file XLSX.utils.sheet_to_html of the component Excel-preview. This manipulation causes cross site scripting. The identification of this vulnerability is CVE-2026-45318. It is possible to initiate the attack remotely. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability has been found in open-webui Open WebUI up to 0.9.2 and classified as problematic. Affected by this vulnerability is some unknown processing of the file XLSX.utils.sheet_to_html of the component Excel-preview. The manipulation with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. As an impact it is known to affect integrity. The summary by CVE is:

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.3, his advisory tracks a regression of the original Excel-preview XSS (CVE-2026-44549). The same root cause — XLSX.utils.sheet_to_html() output rendered via {@html excelHtml} without DOMPurify — was reintroduced sometime after v0.8.0 and is exploitable again This vulnerability is fixed in 0.9.3.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-45318 since 05/11/2026. The exploitation appears to be easy. The attack can be launched remotely. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1059.007 according to MITRE ATT&CK.

Upgrading to version 0.9.3 eliminates this vulnerability.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.4

VulDB Base Score: 3.5
VulDB Temp Score: 3.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.4
CNA Vector (GitHub_M): 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Cross site scripting
CWE: CWE-79 / CWE-94 / CWE-74
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Open WebUI 0.9.3

Timelineinfo

05/11/2026 CVE reserved
05/16/2026 +5 days Advisory disclosed
05/16/2026 +0 days VulDB entry created
05/16/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: GHSA-hcwp-82g6-8wxc
Status: Confirmed

CVE: CVE-2026-45318 (🔒)
GCVE (CVE): GCVE-0-2026-45318
GCVE (VulDB): GCVE-100-364279

Entryinfo

Created: 05/16/2026 06:46
Changes: 05/16/2026 06:46 (66)
Complete: 🔍
Cache ID: 216::103

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