CVE-2026-21883

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.

CVSS

No CVSS.

References

Link	Resource
https://github.com/bokeh/bokeh/commit/cedd113b0e271b439dce768671685cf5f861812e
https://github.com/bokeh/bokeh/security/advisories/GHSA-793v-589g-574v
https://aydinnyunus.github.io/2026/01/24/bokeh-websocket-hijacking-cve-2026-21883/

Configurations

No configuration.

History

No history.

Information

Published : 2026-01-08 02:15

Updated : 2026-01-23 15:16

NVD link : CVE-2026-21883

Mitre link : CVE-2026-21883

CVE.ORG link : CVE-2026-21883

JSON object : View

Products Affected

No product.

CWE

CWE-1385

Missing Origin Validation in WebSockets

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