How severe is CVE-2026-27736?

CVE-2026-27736 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-27736 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-27736?

CVE-2026-27736 affects Bigbluebutton. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-27736?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-27736 have an EU (EUVD) identifier?

Yes. CVE-2026-27736 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8686.

When was CVE-2026-27736 published?

CVE-2026-27736 was published on 2026-02-25 and last updated on 2026-06-17.

CVE-2026-27736

CVE-2026-27736 is a medium-severity vulnerability in Bigbluebutton with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-601.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
EPSS exploit prediction: 0% (4th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-8686
Weakness: CWE-601
Affected product: Bigbluebutton
Published: 2026-02-25
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-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 patches the issue. No known workarounds are available.
How severe is CVE-2026-27736?: CVE-2026-27736 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-27736 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-27736?: CVE-2026-27736 affects Bigbluebutton. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-27736?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-27736 have an EU (EUVD) identifier?: Yes. CVE-2026-27736 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8686.
When was CVE-2026-27736 published?: CVE-2026-27736 was published on 2026-02-25 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:bigbluebutton:bigbluebutton:*:*:*:*:*:*:*:*

More vulnerabilities in Bigbluebutton

CVE-2020-27602 — Critical (CVSS 9.8): BigBlueButton before 2.2.7 does not have a protection mechanism for separator injection in meetingId, userId, and…
CVE-2020-27605 — Critical (CVSS 9.8): BigBlueButton through 2.2.28 uses Ghostscript for processing of uploaded EPS documents, and consequently may be subject…
CVE-2020-12443 — Critical (CVSS 9.8): BigBlueButton before 2.2.6 allows remote attackers to read arbitrary files because the presfilename (lowercase) value…
CVE-2020-27613 — High (CVSS 8.4): The installation procedure in BigBlueButton before 2.2.28 (or earlier) uses ClueCon as the FreeSWITCH password, which…
CVE-2025-61602 — High (CVSS 7.5): BigBlueButton is an open-source virtual classroom. A denial-of-service (DoS) vulnerability in versions prior to 3.0.13…
CVE-2025-61601 — High (CVSS 7.5): BigBlueButton is an open-source virtual classroom. A Denial of Service (DoS) vulnerability in versions prior to 3.0.13…

All CVEs affecting Bigbluebutton →

Other CWE-601 (Open Redirect) vulnerabilities

CVE-2018-3774 — Critical (CVSS 10.0): Incorrect parsing in url-parse <1.4.3 returns wrong hostname which leads to multiple vulnerabilities such as SSRF, Open…
CVE-2019-25282 — Critical (CVSS 9.8): V-SOL GPON/EPON OLT Platform v2.03 contains an open redirect vulnerability in the script that allows attackers to…
CVE-2020-36912 — Critical (CVSS 9.8): Plexus anblick Digital Signage Management 3.1.13 contains an open redirect vulnerability in the 'PantallaLogin' script…
CVE-2025-43526 — Critical (CVSS 9.8): This issue was addressed with improved URL validation. This issue is fixed in Safari 26.2, macOS Tahoe 26.2. On a Mac…
CVE-2025-55031 — Critical (CVSS 9.8): Malicious pages could use Firefox for iOS to pass FIDO: links to the OS and trigger the hybrid passkey transport. An…
CVE-2024-22891 — Critical (CVSS 9.8): Nteract v.0.28.0 was discovered to contain a remote code execution (RCE) vulnerability via the Markdown link.

Browse all CWE-601 (Open Redirect) vulnerabilities →