CVE-2025-0503Network attack vector

Deleted-DM metadata disclosure via endpoint filter failure

Published Feb 14, 2025 · Updated Feb 14, 2025

Information disclosure in Mattermost 9.11.0 through 9.11.6 allows remote authenticated users to infer deleted-DM user IDs and metadata. The deleted channels endpoint returns direct-message channels that its response filter fails to exclude when those channels carry a deletion marker set manually in the database. A valid account and that exceptional database state are required, and exposure is limited to user identifiers and associated direct-message metadata.

CVSS severity3.1
Low
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Mattermost 9.11.0 through 9.11.6 allows remote authenticated users to infer deleted-DM user IDs and metadata. The deleted channels endpoint returns direct-message channels that its response filter fails to exclude when those channels carry a deletion marker set manually in the database. A valid account and that exceptional database state are required, and exposure is limited to user identifiers and associated direct-message metadata.

The record

CVE
CVE-2025-0503
Published
Feb 14, 2025
Updated
Feb 14, 2025
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-754, T1087
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 14, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 14, 2025Record 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=9.11.0 <=9.11.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mattermost · Mattermostversion=9.11.0 <=9.11.6

Published CVSS scores

3.1Mattermost, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

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-754Improper Check for Unusual or Exceptional Conditions
T1087Account Discovery

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

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Your stack

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