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Vulnerabilities

Vulnerability · CVE-2026-27736

BigBlueButton is an open-source virtual classroom.

Published Feb 25, 2026 · catalog updated Jun 17, 2026 · BigBlueButton is an open-source

Check if you run it

No confirmed exploitation is on record for CVE-2026-27736. EPSS is 0.26%. Act only if a listed version of BigBlueButton is an open-source is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (BigBlueButton is an open-source).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Medium6.1
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.26%
Remediation
Advisory link
Affected products
cpe bigbluebutton/bigbluebutton

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe bigbluebutton/bigbluebuttonversion unspecified

How to fix CVE-2026-27736

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-27736. EPSS is 0.26%. Act only if a listed version of BigBlueButton is an open-source is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-601: URL Redirection to Untrusted Site (Open Redirect). EPSS 0.26%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Feb 25, 2026 · NIST NVD

    Detected

    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.

  2. Jun 17, 2026 · NIST NVD

    Updated

    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.

Sources

  • CVE.orgVulnerability recordCVE-2026-27736

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-27736

    30-day exploitation probability 0.3%

    first.org
  • NIST NVDVulnerability recordCVE-2026-27736

    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 patche

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.