CVE-2023-49809Network attack vector

Authenticated service interruption via null add request

Published Dec 12, 2023 · Updated Aug 2, 2024

Denial of service in the Mattermost Todo plugin in Mattermost 8.1.5 and earlier allows remote authenticated users to crash the plugin. The /add POST handler does not reject a null request body before processing it, causing the Todo plugin to crash. Any ordinary member can repeat the request; Mattermost plugin health checks eventually disable the repeatedly failing plugin, interrupting Todo functions.

CVSS severity4.3
Medium
EPSS probability0.64%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Denial of service in the Mattermost Todo plugin in Mattermost 8.1.5 and earlier allows remote authenticated users to crash the plugin. The /add POST handler does not reject a null request body before processing it, causing the Todo plugin to crash. Any ordinary member can repeat the request; Mattermost plugin health checks eventually disable the repeatedly failing plugin, interrupting Todo functions.

The record

CVE
CVE-2023-49809
Published
Dec 12, 2023
Updated
Aug 2, 2024
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-400, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 12, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=0 <=8.1.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mattermost · Mattermostversion=0 <=8.1.5

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.3Mattermost, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 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
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo