BigBlueButton up to 3.0.20 Checksum Validation CreateMeeting.java presentationUploadExternalUrl unrestricted upload

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.0$0-$5k1.40

Summaryinfo

A vulnerability classified as critical was found in BigBlueButton up to 3.0.20. Affected by this vulnerability is an unknown functionality of the file CreateMeeting.java of the component Checksum Validation. Such manipulation of the argument presentationUploadExternalUrl leads to unrestricted upload. This vulnerability is referenced as CVE-2026-46353. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability was found in BigBlueButton up to 3.0.20. It has been rated as critical. Affected by this issue is an unknown function of the file CreateMeeting.java of the component Checksum Validation. The manipulation of the argument presentationUploadExternalUrl with an unknown input leads to a unrestricted upload vulnerability. Using CWE to declare the problem leads to CWE-434. The product allows the attacker to upload or transfer files of dangerous types that can be automatically processed within the product's environment. Impacted is confidentiality, integrity, and availability. CVE summarizes:

BigBlueButton is an open-source virtual classroom. Prior to 3.0.21, bbb-web checksum validation could be bypassed when a presentationUploadExternalUrl parameter was supplied to API request handling in CreateMeeting.java and ValidationService.java, allowing a user to send valid requests to some endpoints without a checksum. This issue is fixed in version 3.0.21.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-46353 since 05/13/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1608.002 by the MITRE ATT&CK project.

Upgrading to version 3.0.21 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 7.0

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Unrestricted upload
CWE: CWE-434 / CWE-284 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Upgrade: BigBlueButton 3.0.21

Timelineinfo

05/13/2026 CVE reserved
07/16/2026 +64 days Advisory disclosed
07/16/2026 +0 days VulDB entry created
07/16/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-46353 (🔒)
GCVE (CVE): GCVE-0-2026-46353
GCVE (VulDB): GCVE-100-379610

Entryinfo

Created: 07/16/2026 20:34
Changes: 07/16/2026 20:34 (54)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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