CVE-2026-45398 Details
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, _validate_collection_access() checks the user-memory-* and file-* collection name prefixes but does not check knowledge base collections, which use raw UUIDs as collection names. Any authenticated user who knows a private knowledge base UUID can read its content through the retrieval query endpoints, even though the knowledge API correctly denies that user access. The same gap affects the retrieval write endpoints (/process/text, /process/file, /process/files/batch, /process/web, /process/youtube), allowing an attacker to inject content into or overwrite another user's knowledge base. This vulnerability is fixed in 0.9.5.
View at NVD
Exploit prediction scoring system (EPSS) score for CVE-2026-45398
EPSS (Exploit Prediction Scoring System): EPSS predicts the likelihood that a vulnerability will be exploited in the wild. A higher percentage means a greater chance of an exploit occurring. The EPSS model produces a probability score between 0 and 1 (0 and 100%).
0.33 Probability of exploitation activity being observed over the next 30 days (25th percentile)
CVSS score for CVE-2026-45398
CVSS (Common Vulnerability Scoring System): An open framework owned and managed by FIRST.Org, Inc. that assigns a numerical score from 0 to 10 to software vulnerabilities to indicate their severity.
7.5 High
Products affected by CVE-2026-45398
Open Webui 0.3.15
Open Webui 0.3.30
Open Webui 0.3.32
Open Webui 0.3.35
Open Webui 0.4.7
DVE Score by Bitsight AI
DVE scores complement traditional static scoring systems like CVSS with Bitsight AI powered real-time threat intelligence and underground cyber criminal activity so that security teams can reduce alert fatigue and focus on vulnerabilities most likely to be exploited.
Low
More on DVE scores

CVE-2026-45398 Global Footprint

Top 10 Identified Countries

Country Observations Percentage
US 1,102 24.63%
DE 700 15.64%
CN 569 12.72%
FR 201 4.49%
SG 176 3.93%
RU 169 3.78%
GB 147 3.28%
KR 128 2.86%
NL 94 2.10%
JP 87 1.94%

Is CVE-2026-45398 part of your extended attack surface? Bitsight helps security leaders rapidly identify exposure and detect threats in order to prioritize, communicate, and mitigate risk.

View interactive product tours

CVE-2026-45398 Industry Footprint

Top 10 Identified Industries

*Service provider organizations (typically Technology and Telecommunications) are disproportionally represented in the results given their upstream ownership of end-user infrastructure. See our FAQs.

Industry* Observations Percentage
Technology 2,718 83.81%
Telecommunications 393 12.12%
Education 57 1.76%
Retail 14 0.43%
Government/Politics 12 0.37%
Utilities 11 0.34%
Consumer Goods 10 0.31%
Business Services 7 0.22%
Media/Entertainment 4 0.12%
Finance 3 0.09%

Bitsight Data Discovery and Continuous Threat Scanning

Bitsight, the leading provider in Cyber Risk Management, introduced the next-generation internet scanner Bitsight Groma in May 2024. This technology continuously scans the entire internet to discover assets, collect asset attribution evidence, and identify an ever-growing set of security observations, such as vulnerabilities and misconfigurations. Groma’s scanning activities presently encompass:


  • 40 million-plus monitored organizations
  • 250 million-plus host names
  • 4 billion-plus routable IPv4 and IPv6 addresses

Greynoise’s recent study testifies the speed of Bitsight Groma.

Learn more about Bitsight Groma
Bitsight data discovery
Governance charcoal background

How we use Bitsight Groma data 

Empower Security Research

Bitsight TRACE team investigates security incidents and identifies vulnerabilities and threats.

View latest security research 

See Your External Attack Surface

See what you’re up against across the expanding attack surface. Prioritize what matters most. And mitigate where you’re most vulnerable.

External Attack Surface Management