CVE-2026-27736 BigBlueButton has Open Redirect vulnerability in ApiController
Attackers can redirect users to malicious sites via unvalidated errorRedirectUrl parameter in BigBlueButton's ApiController.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-27736?
CVE-2026-27736 is a medium-severity vulnerability in bigbluebutton, published on 25 Feb 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-601
Which versions are affected by CVE-2026-27736?
It affects 1 product.
Products include Bigbluebutton Bigbluebutton.
How do I fix CVE-2026-27736?
No fix has been published for CVE-2026-27736 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-27736 being exploited?
There is no known exploitation of CVE-2026-27736 in the wild and no public exploit code.
Other vulnerabilities in bigbluebutton
Sources
Also known as GHSA-65cv-rg9f-qqrx.