CVE-2026-10103 (GCVE-0-2026-10103)

Vulnerability from cvelistv5 – Published: 2026-07-13 07:57 – Updated: 2026-07-13 07:57
VLAI
Title
Authenticated remote cluster can modify or delete posts it does not own in Mattermost Connected Workspaces shared channels
Summary
Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to verify post ownership in the shared channel inbound sync handler, which allows an authenticated remote cluster to modify or delete posts authored by local users or other remotes via crafted sync messages referencing arbitrary post IDs in channels shared with that remote.. Mattermost Advisory ID: MMSA-2026-00689
Severity
4.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
CWE
  • CWE-639 - Authorization Bypass Through User-Controlled Key
Assigner
References
URL Tags
https://mattermost.com/security-updates vendor-advisory
Impacted products
Vendor Product Version
Mattermost Mattermost Affected: 11.7.0 , ≤ 11.7.2 (semver)
Affected: 11.6.0 , ≤ 11.6.4 (semver)
Affected: 10.11.0 , ≤ 10.11.19 (semver)
Unaffected: 11.8.0
Unaffected: 11.7.3
Unaffected: 11.6.5
Unaffected: 10.11.20
Create a notification for this product.
Credits
ratrarity
Show details on NVD website
To clipboard 

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  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.