6.5

CVE-2026-6850

EPSS 0.24%
Veröffentlicht 13.07.2026 08:13:02
Zuletzt bearbeitet 13.07.2026 21:42:01
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Crafted message attachment causes client-side denial of service via markdown parser regex backtracking in Mattermost

Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to validate the length and content of message attachment field values, which allows an authenticated attacker to cause a denial of service for all users in a channel via a post containing a specially crafted payload that triggers catastrophic backtracking in the client-side markdown parser.. Mattermost Advisory ID: MMSA-2026-00658

Betroffene Produkte Warnungen 0 Metriken 2 CWE 1 Referenzen 4

NVD 3 VulnDex Vulnerability Enrichment 1

Daten sind bereitgestellt durch National Vulnerability Database (NVD)

Mattermost ≫ Mattermost Server Version >= 10.11.0 < 10.11.20

Mattermost ≫ Mattermost Server Version >= 11.6.0 < 11.6.5

Mattermost ≫ Mattermost Server Version >= 11.7.0 < 11.7.3

VulnDex Vulnerability Enrichment

Diese Information steht angemeldeten Benutzern zur Verfügung.

Zu dieser CVE wurde keine Warnung gefunden.

EPSS Metriken
Typ	Quelle	Score	Percentile
EPSS	FIRST.org	0.24%	0.15

CVSS Metriken
Quelle	Base Score	Exploit Score	Impact Score	Vector String
responsibledisclosure@mattermost.com	6.5	2.8	3.6	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE-1333 Inefficient Regular Expression Complexity

The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.

https://mattermost.com/security-updates

Vendor Advisory

https://nvd.nist.gov/vuln/detail/CVE-2026-6850

CVE Source (NVD)

https://cveawg.mitre.org/api/cve/CVE-2026-6850

CVE Source (JSON)

https://euvd.enisa.europa.eu/vulnerability/CVE-2026-6850

EUVD