How severe is CVE-2026-2299?

CVE-2026-2299 has a CVSS 3.x base score of 4.2, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-2299 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-2299?

CVE-2026-2299 primarily affects Mattermost Google Drive. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-2299?

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

Does CVE-2026-2299 have an EU (EUVD) identifier?

Yes. CVE-2026-2299 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39540.

When was CVE-2026-2299 published?

CVE-2026-2299 was published on 2026-06-25 and last updated on 2026-08-11.

CVE-2026-2299

CVE-2026-2299 is a medium-severity vulnerability in Mattermost Google Drive with a CVSS 3.x base score of 4.2. 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-862.

Key facts

Severity: Medium (CVSS 3.x base score 4.2)
EPSS exploit prediction: 0% (9th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-39540
Weakness: CWE-862
Affected product: Mattermost Google Drive
Published: 2026-06-25
Last modified: 2026-08-11

Description

The Mattermost Google Drive plugin before version 1.1.0 fails to validate channel membership in the file creation endpoint, allowing authenticated users with a connected Google account to share Google Drive files to unauthorized private channels and disclose private channel membership.

Frequently asked questions

What is CVE-2026-2299?: The Mattermost Google Drive plugin before version 1.1.0 fails to validate channel membership in the file creation endpoint, allowing authenticated users with a connected Google account to share Google Drive files to unauthorized private channels and disclose private channel membership.
How severe is CVE-2026-2299?: CVE-2026-2299 has a CVSS 3.x base score of 4.2, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-2299 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-2299?: CVE-2026-2299 primarily affects Mattermost Google Drive. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-2299?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-2299 have an EU (EUVD) identifier?: Yes. CVE-2026-2299 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39540.
When was CVE-2026-2299 published?: CVE-2026-2299 was published on 2026-06-25 and last updated on 2026-08-11.

References

https://github.com/mattermost/mattermost-plugin-google-drive/releases/tag/v1.1.0

Affected products (3)

cpe:2.3:a:mattermost:google_drive:*:*:*:*:*:mattermost:*:*
cpe:2.3:a:mattermost:google_drive:1.1.0:rc1:*:*:*:mattermost:*:*
cpe:2.3:a:mattermost:google_drive:1.1.0:rc2:*:*:*:mattermost:*:*

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