CVE-2026-46351Network attack vector

Session impersonation via predictable conference tokens

Published Jul 16, 2026 · Updated Jul 16, 2026

Insufficient randomness in BigBlueButton before 3.0.21 allows remote authenticated users to predict session tokens and impersonate users. ApiController generated internal user IDs, authentication tokens, and 16-character conference session tokens with Apache Commons Lang RandomStringUtils rather than a cryptographically secure generator. Existing session access is required; successful prediction permits another participant's conference identity to be assumed, with no reported service interruption.

CVSS severity8.1
High
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insufficient randomness in BigBlueButton before 3.0.21 allows remote authenticated users to predict session tokens and impersonate users. ApiController generated internal user IDs, authentication tokens, and 16-character conference session tokens with Apache Commons Lang RandomStringUtils rather than a cryptographically secure generator. Existing session access is required; successful prediction permits another participant's conference identity to be assumed, with no reported service interruption.

The record

CVE
CVE-2026-46351
Published
Jul 16, 2026
Updated
Jul 16, 2026
Vendor
BigBlueButton Inc.
Product
BigBlueButton
Classifications
CWE-330, T1550.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.0.21

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

BigBlueButton Inc. · BigBlueButtonversion=< 3.0.21

Published CVSS scores

8.1GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-330Use of Insufficiently Random Values
T1550.001Use Alternate Authentication Material: Application Access Token

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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