CVE-2023-5522Network attack vector

Mobile app hang via unbounded Markdown elements

Published Oct 17, 2023 · Updated Sep 5, 2024

Resource exhaustion in Mattermost Mobile before 2.8.0 allows remote attackers to freeze the app with an emoji-heavy channel post. The mobile Markdown renderer creates every emoji element without enforcing a maximum element count, exhausting rendering resources as the post is displayed. The attacker must be able to post to a channel, and a user must view that channel; the consequence is limited to an app hang.

CVSS severity4.3
Medium
EPSS probability0.38%
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 Mobile before 2.8.0 allows remote attackers to freeze the app with an emoji-heavy channel post. The mobile Markdown renderer creates every emoji element without enforcing a maximum element count, exhausting rendering resources as the post is displayed. The attacker must be able to post to a channel, and a user must view that channel; the consequence is limited to an app hang.

The record

CVE
CVE-2023-5522
Published
Oct 17, 2023
Updated
Sep 5, 2024
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-400, T1499.003
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 17, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 5, 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 <2.8.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mattermost · Mattermostversion=0 <2.8.0

Published CVSS scores

4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
4.3MattermostCVSS: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
T1499.003Application Exhaustion Flood

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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