CVE-2026-5132

EUVD-2026-77370
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to limit size of unpacked SDP messages compressed with zlib, which allows attacker to deny service or crash server via sending many SDP messages that unpack to large size.. Mattermost Advisory ID: MMSA-2026-00643
Data Amplification
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
MattermostCNA
6.5 MEDIUM
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
mattermostmattermost
𝑥
≤ 11.9.0
CNA
mattermostmattermost
11.8.0 ≤
𝑥
≤ 11.8.4
CNA
mattermostmattermost
11.7.0 ≤
𝑥
≤ 11.7.7
CNA
mattermostmattermost
10.11.0 ≤
𝑥
≤ 10.11.22
CNA
Common Weakness Enumeration
References
https://mattermost.com/security-updates