CVEvulnerability

CVE-2026-21883

4.5 MEDIUM Published 2026-01-08 Modified 2026-06-17 Official page ↗
Status
Analyzed
Published
2026-01-08
Last modified
2026-06-17
Assigner
[email protected]
CVSS 4.0 ([email protected])
4.5 MEDIUM — CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1 ([email protected])
5.4 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Weaknesses
CWE-1385

Description

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.

Affected configurations

• bokeh bokeh (< 3.8.2)

Related

Weakness · CWE (1)

  • CWE-1385 Missing Origin Validation in WebSockets weakness

References