CVE-2026-27736

BigBlueButton has Open Redirect vulnerability in ApiController

MEDIUM
6.1
CVSS Score
Published: February 25, 2026 at 04:27 PM UTC
Updated: June 17, 2026 at 10:27 AM UTC
1 product affected across 1 vendorBigbluebutton

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Severity
MEDIUM6.1
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

BigBlueButton is an open-source virtual classroom. In versions on the 3.x branch prior to 3.0.20, the string received with errorRedirectUrl lacks validation, using it directly in the respondWithRedirect function leads to an Open Redirect vulnerability. BigBlueButton 3.0.20 patches the issue. No known workarounds are available.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 3.0.20
Affected range stops below 3.0.20, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.1MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-601

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