CVE-2023-5196Network attack vector

Authenticated service interruption via oversized notification properties

Published Sep 29, 2023 · Updated Sep 20, 2024

Resource exhaustion in Mattermost 7.8.9 and earlier, 8.0.1 and earlier, and 8.1.0 allows remote authenticated users to cause a temporary outage. The server omits length enforcement for some channel notification_prop values, so an oversized value consumes abnormal computing resources. A low-privileged account must submit the crafted property; the bounded consequence is temporary unavailability, not data access or modification.

CVSS severity6.5
Medium
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Mattermost 7.8.9 and earlier, 8.0.1 and earlier, and 8.1.0 allows remote authenticated users to cause a temporary outage. The server omits length enforcement for some channel notification_prop values, so an oversized value consumes abnormal computing resources. A low-privileged account must submit the crafted property; the bounded consequence is temporary unavailability, not data access or modification.

The record

CVE
CVE-2023-5196
Published
Sep 29, 2023
Updated
Sep 20, 2024
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 29, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 20, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=7.8.9
  2. Affected versionversion=0 <=8.0.1
  3. Affected versionversion=8.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mattermost · Mattermostversion=0 <=7.8.9; version=0 <=8.0.1; version=8.1.0

Published CVSS scores

6.5MattermostCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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