CVE-2026-5132

Published: September 14th, 2026
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
MEDIUM
CVSS v3: 6.5

Status

DocFilters Release Package State Justification Comment
daily zlib (1.3) Needs Triage
26.3 zlib (1.3) Needs Triage
26.2 zlib (1.3) Needs Triage
26.1 zlib (1.3) Needs Triage
25.4 zlib (1.3) Needs Triage
25.3 zlib (1.3) Needs Triage
25.2 zlib (1.3) Needs Triage
25.1 zlib (1.3) Needs Triage
24.4 zlib (1.3) Needs Triage
24.4.0 zlib (1.3) Needs Triage
24.3 zlib (1.3) Needs Triage
24.2 zlib (1.3) Needs Triage
24.1 zlib (1.3) Needs Triage
23.3 zlib (1.3) Needs Triage
23.2 zlib (1.2.12) Needs Triage
23.1 zlib (1.2.12) Needs Triage
22.4 zlib (1.2.12) Needs Triage
22.3 zlib (1.2.12) Needs Triage
22.2 zlib (1.2.12) Needs Triage
22.1 zlib (1.2.11) Needs Triage
21.11 zlib (1.2.11) Needs Triage
21.8 zlib (1.2.11) Needs Triage
21.5.0 zlib (1.2.11) Needs Triage
21.2.0 zlib (1.2.11) Needs Triage
11.4.19.3667 zlib (1.2.11) Needs Triage
11.4.18.3599 zlib (1.2.11) Needs Triage
11.4.16.3445 zlib (1.2.11) Needs Triage
11.4.15.3368 zlib (1.2.11) Needs Triage
11.4.14.3263 zlib (1.2.11) Needs Triage
11.4.13.3179 zlib (1.2.11) Needs Triage
11.4.12.3054 zlib (1.2.11) Needs Triage
11.4.11.3040 zlib (1.2.11) Needs Triage
11.4.11.2990 zlib (1.2.11) Needs Triage
11.4.10.2934 zlib (1.2.11) Needs Triage
11.4.9.2878 zlib (1.2.11) Needs Triage
11.4.8.2822 zlib (1.2.11) Needs Triage

Severity score breakdown

Attack Complexity
LOW
Attack Vector
NETWORK
Availability Impact
HIGH
Base Score
6.5
Base Severity
MEDIUM
Confidentiality Impact
NONE
Integrity Impact
NONE
Privileges Required
LOW
Scope
UNCHANGED
User Interaction
NONE
Vector String
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Version
3.1

References