Mattermost versions 11.10.x <= 11.10.0, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10 fail to cap the number and size of mention keys stored in a user's notification properties, and to bound the quadratic multibyte-keyword matching performed for each post, which allows an authenticated user to degrade post-processing latency and consume excessive CPU on behalf of other members of any channel they share via storing an oversized notify_props.mention_keys list on their own profile.. Mattermost Advisory ID: MMSA-2026-00773
Metrics
Affected Vendors & Products
References
| Link | Providers |
|---|---|
| https://mattermost.com/security-updates |
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History
Sat, 17 Oct 2026 16:30:00 +0000
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Mattermost
Mattermost mattermost |
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Mattermost
Mattermost mattermost |
Fri, 16 Oct 2026 13:30:00 +0000
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ssvc
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Fri, 16 Oct 2026 07:15:00 +0000
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| Description | Mattermost versions 11.10.x <= 11.10.0, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10 fail to cap the number and size of mention keys stored in a user's notification properties, and to bound the quadratic multibyte-keyword matching performed for each post, which allows an authenticated user to degrade post-processing latency and consume excessive CPU on behalf of other members of any channel they share via storing an oversized notify_props.mention_keys list on their own profile.. Mattermost Advisory ID: MMSA-2026-00773 | |
| Title | Uncapped mention keys in user notification properties allow CPU exhaustion during post processing | |
| Weaknesses | CWE-770 | |
| References |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: Mattermost
Published: 2026-10-16T07:00:12.550Z
Updated: 2026-10-16T12:00:11.330Z
Reserved: 2026-08-14T10:56:08.014Z
Link: CVE-2026-19867
Updated: 2026-10-16T12:00:04.975Z
Status : Awaiting Analysis
Published: 2026-10-16T07:17:13.353
Modified: 2026-10-16T19:23:18.623
Link: CVE-2026-19867
No data.