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
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mattermost | Mattermost | unaffected |
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Project Subscriptions
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Advisories
No advisories yet.
Fixes
Solution
Update Mattermost to versions 11.10.0, 11.9.1, 11.8.5, 11.7.8, 10.11.23 or higher.
Workaround
No workaround given by the vendor.
References
| Link | Providers |
|---|---|
| https://mattermost.com/security-updates |
|
History
Mon, 14 Sep 2026 10:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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 | |
| Title | Unbounded zlib decompression in Calls SDP WebSocket messages | |
| Weaknesses | CWE-409 | |
| References |
| |
| Metrics |
cvssV3_1
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Mattermost
Published:
Updated: 2026-09-14T10:41:42.387Z
Reserved: 2026-03-30T09:58:00.256Z
Link: CVE-2026-5132
Vulnrichment
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NVD
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Redhat
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OpenCVE Enrichment
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Weaknesses