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Low 3.9Published Aug 17, 2026

CVE-2026-16044Insufficient validation of guest board admin privileges on archive import

Updated under an hour ago ()

Does this affect you?

It affects Mattermost and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21 fail to prevent guest users from receiving Board Admin privileges during board archive import which allows a board member to escalate a guest user to Board Admin via importing a crafted .boardarchive file. Mattermost Advisory ID: MMSA-2026-00672

CVSS
3.9 LOW (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
Weakness (CWE)
CWE-863
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
Mattermost
NVD analysis
Analyzed
Record last updated
Aug 17, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
Mattermost Mattermost
mattermost:mattermost (from the name)
from 11.7.0 through 11.7.6; from 10.11.0 through 10.11.21; 11.9.0 not affected; 11.7.7 not affected; 10.11.22 not affected
CNA record
mattermost mattermost_server
mattermost:mattermost_server
from 10.11.0 before 10.11.22; from 11.7.0 before 11.7.7
NVD

References

  • vendor-advisory

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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