VULNERABILITY INTELLIGENCE

CVE-2026-2455

CVSS score4.3 MEDIUM
EPSS probability0.17%
CISA KEVNot currently listed
Published2026-03-16
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Description

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to canonicalize IPv4-mapped IPv6 addresses before reserved IP validation which allows an attacker to perform SSRF attacks against internal services via IPv4-mapped IPv6 literals (e.g., [::ffff:127.0.0.1]).. Mattermost Advisory ID: MMSA-2026-00585

Weakness classification

  • responsibledisclosure@mattermost.com: CWE-918

Primary references