How severe is CVE-2023-42803?

CVE-2023-42803 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2023-42803 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-42803?

CVE-2023-42803 primarily affects Bigbluebutton. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-42803?

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

When was CVE-2023-42803 published?

CVE-2023-42803 was published on 2023-10-30 and last updated on 2026-06-17.

CVE-2023-42803

CVE-2023-42803 is a medium-severity vulnerability in Bigbluebutton with a CVSS 3.x base score of 5.3. 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-434.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 1% (41st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-434
Affected product: Bigbluebutton
Published: 2023-10-30
Last modified: 2026-06-17

Description

BigBlueButton is an open-source virtual classroom. BigBlueButton prior to version 2.6.0-beta.2 is vulnerable to unrestricted file upload, where the insertDocument API call does not validate the given file extension before saving the file, and does not remove it in case of validation failures. BigBlueButton 2.6.0-beta.2 contains a patch. There are no known workarounds.

Frequently asked questions

What is CVE-2023-42803?: BigBlueButton is an open-source virtual classroom. BigBlueButton prior to version 2.6.0-beta.2 is vulnerable to unrestricted file upload, where the insertDocument API call does not validate the given file extension before saving the file, and does not remove it in case of validation failures. BigBlueButton 2.6.0-beta.2 contains a patch. There are no known workarounds.
How severe is CVE-2023-42803?: CVE-2023-42803 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2023-42803 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-42803?: CVE-2023-42803 primarily affects Bigbluebutton. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-42803?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-42803 published?: CVE-2023-42803 was published on 2023-10-30 and last updated on 2026-06-17.

References

Affected products (6)

cpe:2.3:a:bigbluebutton:bigbluebutton:*:*:*:*:*:*:*:*
cpe:2.3:a:bigbluebutton:bigbluebutton:2.6.0:alpha1:*:*:*:*:*:*
cpe:2.3:a:bigbluebutton:bigbluebutton:2.6.0:alpha2:*:*:*:*:*:*
cpe:2.3:a:bigbluebutton:bigbluebutton:2.6.0:alpha3:*:*:*:*:*:*
cpe:2.3:a:bigbluebutton:bigbluebutton:2.6.0:alpha4:*:*:*:*:*:*
cpe:2.3:a:bigbluebutton:bigbluebutton:2.6.0:beta1:*:*:*:*:*:*

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