CVE-2022-3257Public exploitNetwork attack vector

Authenticated service interruption via crafted GIF processing

Published Sep 23, 2022 · Updated Dec 6, 2024

Uncontrolled resource consumption in Mattermost 7.1.x and earlier allows remote authenticated users to interrupt the server via a crafted GIF. The server processes a GIF uploaded while a post is being drafted without sufficient resource bounds, exhausting server resources. A valid user session and file-upload access are required; the documented consequence is limited to server-side availability.

CVSS severity3.1
Low
EPSS probability1.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled resource consumption in Mattermost 7.1.x and earlier allows remote authenticated users to interrupt the server via a crafted GIF. The server processes a GIF uploaded while a post is being drafted without sufficient resource bounds, exhausting server resources. A valid user session and file-upload access are required; the documented consequence is limited to server-side availability.

The record

CVE
CVE-2022-3257
Published
Sep 23, 2022
Updated
Dec 6, 2024
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-400, CWE-434, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 23, 2022CVE publishedPublication date reported by the CVE source.
  2. Dec 6, 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=unspecified <=7.1.x

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mattermost · Mattermostversion=unspecified <=7.1.x

Published CVSS scores

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

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
CWE-434Unrestricted Upload of File with Dangerous Type
T1499.004Application or System Exploitation

Public exploit references

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

Technologies

Your stack

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Your stack

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