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CVE-2026-18256

CVE-2026-18256 · Private team metadata disclosure via the team search API

This page contains facts from public vulnerability sources. Check the original advisory before updating.

Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to properly restrict private teams from public team search results, which allows an authenticated user without permission to list private teams to disclose the ID, name, and display name of private teams via a modified team search request. Mattermost Advisory ID: MMSA-2026-00748

CVSS 4.3 · Medium · EPSS 0.2%

Published
Updated

Affected products and versions

  • mattermost

    Versions
    • ≥ 11.10.0, ≤ 11.10.0: Affected (semver)
    • ≥ 11.7.0, ≤ 11.7.9: Affected (semver)
    • ≥ 11.9.0, ≤ 11.9.1: Affected (semver)
    • ≥ 11.8.0, ≤ 11.8.5: Affected (semver)
    • 11.11.0: Not affected
    • 11.10.1: Not affected
    • 11.7.10: Not affected
    • 11.9.2: Not affected
    • 11.8.6: Not affected

    No fix published

Original sources

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