CVE-2026-10103— Authenticated remote cluster can modify or delete posts it does not own in Mattermost Connected Workspaces shared channels
Possible ATT&CK Techniques 1AI
T1133 · External Remote ServicesAffected Version Matrix 7
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Mattermost | Mattermost | 11.7.0≤ 11.7.2 | affected |
11.6.0≤ 11.6.4 | affected | ||
10.11.0≤ 10.11.19 | affected | ||
11.8.0 | unaffected | ||
11.7.3 | unaffected | ||
11.6.5 | unaffected | ||
10.11.20 | unaffected |
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I. Basic Information for CVE-2026-10103
Vulnerability Information
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Vulnerability Title
Authenticated remote cluster can modify or delete posts it does not own in Mattermost Connected Workspaces shared channels
Source: NVD (National Vulnerability Database)
Vulnerability Description
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
Source: NVD (National Vulnerability Database)
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Source: NVD (National Vulnerability Database)
Vulnerability Type
通过用户控制密钥绕过授权机制
Source: NVD (National Vulnerability Database)
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| Mattermost | Mattermost | 11.7.0 ~ 11.7.2 | - |
II. Public POCs for CVE-2026-10103
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POCPremium
No public POC found.
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Same Patch Batch · Mattermost · 2026-07-13 · 10 CVEs total
| CVE-2026-6850 | 6.5 MEDIUM | Crafted message attachment causes client-side denial of service via markdown parser regex |
| CVE-2026-10106 | 6.5 MEDIUM | Unauthorized users can trigger interactive post actions in private channels via action coo |
| CVE-2026-9571 | 5.9 MEDIUM | Deactivated user accounts can continue to obtain valid OAuth access tokens via refresh tok |
| CVE-2026-9597 | 5.4 MEDIUM | Deactivated guest accounts can authenticate via magic-link token in Mattermost REST API lo |
| CVE-2026-10085 | 5.4 MEDIUM | Ordinary group/direct message member can enable group_constrained and remove all channel p |
| CVE-2026-9708 | 4.9 MEDIUM | Incoming webhook user attribution via unvalidated webhook owner |
| CVE-2026-6541 | 4.3 MEDIUM | Unscoped updates to other playbooks' metric configuration |
| CVE-2026-9824 | 4.3 MEDIUM | Remote cluster metadata enumeration via /share-channel autocomplete |
| CVE-2026-9820 | 3.8 LOW | Mattermost schemes teams endpoint exposes private team invite IDs |
IV. Related Vulnerabilities
Same product: Mattermost
- CVE-2026-6541
Unscoped updates to other playbooks' metric configuration - CVE-2026-9820
Mattermost schemes teams endpoint exposes private team invit - CVE-2026-9824
Remote cluster metadata enumeration via /share-channel autoc - CVE-2026-9597
Deactivated guest accounts can authenticate via magic-link t - CVE-2026-6850
Crafted message attachment causes client-side denial of serv
Same vendor: Mattermost
- CVE-2026-6541
Unscoped updates to other playbooks' metric configuration - CVE-2026-9820
Mattermost schemes teams endpoint exposes private team invit - CVE-2026-9824
Remote cluster metadata enumeration via /share-channel autoc - CVE-2026-9597
Deactivated guest accounts can authenticate via magic-link t - CVE-2026-6850
Crafted message attachment causes client-side denial of serv
Same weakness: CWE-639
- CVE-2026-58410
ChurchCRM: Improper object-level authorization allows low-pr - CVE-2026-6541
Unscoped updates to other playbooks' metric configuration - CVE-2026-61971
WordPress User Profile Picture plugin <= 2.6.3 - Insecure Di - CVE-2026-57694
WordPress Tutor LMS plugin <= 3.9.13 - Insecure Direct Objec - CVE-2026-9708
Incoming webhook user attribution via unvalidated webhook ow
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