CVE-2026-21883
MEDIUM
GHSA-793v-589g-574v
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Lifecycle Timeline
4Description
Bokeh is an interactive visualization library written in Python. In versions 3.8.1 and below, if a server is configured with an allowlist (e.g., dashboard.corp), an attacker can register a domain like dashboard.corp.attacker.com (or use a subdomain if applicable) and lure a victim to visit it. The malicious site can then initiate a WebSocket connection to the vulnerable Bokeh server. Since the Origin header (e.g., http://dashboard.corp.attacker.com/) matches the allowlist according to the flawed logic, the connection is accepted. Once connected, the attacker can interact with the Bokeh server on behalf of the victim, potentially accessing sensitive data, or modifying visualizations. This issue is fixed in version 3.8.2.
Analysis
Bokeh versions 3.8.1 and below allow attackers to bypass Origin validation in WebSocket connections by registering domains that suffix-match allowlisted domains (e.g., dashboard.corp.attacker.com for allowlist entry dashboard.corp), enabling unauthorized server interaction. Public exploit code exists for this vulnerability, which could allow attackers to access sensitive data or modify visualizations on behalf of victims. …
Sign in for full analysis, threat intelligence, and remediation guidance.
Remediation
Within 30 days: Identify affected systems running Python. In and apply vendor patches as part of regular patch cycle. …
Sign in for detailed remediation steps.
Priority Score
Vendor Status
Share
External POC / Exploit Code
Leaving vuln.today