Is CVE-2026-5132 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-5132?

CVE-2026-5132 has a CVSS v3 severity of MEDIUM (6.5).

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CVE-2026-5132

Description

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