CVE-2026-4915— Server panic via outgoing webhook responses
Possible ATT&CK Techniques 1AI
T1499 · Endpoint Denial of ServiceGet alerts for future matching vulnerabilitiesLog in to subscribe
I. Basic Information for CVE-2026-4915
Vulnerability Information
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Vulnerability Title
Server panic via outgoing webhook responses
Source: NVD (National Vulnerability Database)
Vulnerability Description
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to filter nil elements from outgoing webhook attachment payloads before processing, which allows an authenticated user to cause a denial of service (server process termination) via a crafted webhook callback response containing a null attachment entry.. Mattermost Advisory ID: MMSA-2026-00641
Source: NVD (National Vulnerability Database)
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Source: NVD (National Vulnerability Database)
Vulnerability Type
对因果或异常条件的不恰当检查
Source: NVD (National Vulnerability Database)
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| Mattermost | Mattermost | 11.6.0 ~ 11.6.0 | - |
II. Public POCs for CVE-2026-4915
| # | POC Description | Source Link | Shenlong Link |
|---|
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IV. Related Vulnerabilities
Same product: Mattermost
- CVE-2026-28735
GitHub OAuth Scope Validation - CVE-2026-4635
Persistent notification timing attack causing server denial - CVE-2026-3473
Improper file ownership validation in the Boards API allows - CVE-2026-4646
Insufficient input validation in GitHub plugin API causes de - CVE-2026-3636
Sanitize team member data returned by API
Same vendor: Mattermost
- CVE-2026-28735
GitHub OAuth Scope Validation - CVE-2026-4635
Persistent notification timing attack causing server denial - CVE-2026-3473
Improper file ownership validation in the Boards API allows - CVE-2026-4646
Insufficient input validation in GitHub plugin API causes de - CVE-2026-3636
Sanitize team member data returned by API
Same weakness: CWE-754
- CVE-2026-40094
nimiq-blockchain: network-libp2p untrusted peer can crash ad - CVE-2026-8491
Node View Permissions - Moderately critical - Access bypass - CVE-2026-47315
SAMSUNG Escargot 代码问题漏洞 - CVE-2026-4643
Calling window.close() from server-side content causes crash - CVE-2026-4054
SVG content served through Mattermost image proxy despite Co
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