Signal is active with 2 mentions in latest observed window
Recommended action window: Monitor and triage in normal cycle
NVD 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
Priority
LOW
Exploitation
NONE
PoC
NONE
Patch
NONE
Momentum
NONE
If you run products in this scope, you should treat this CVE as relevant to your environment.
CVE-2026-2455 Server-Side Request Forgery in Mattermost via IPv4-Mapped IPv6 Address Validation Bypass https://vulmon.com/vulnerabilitydetails?qid=CVE-2026-2455
Post summary
A new SSRF vulnerability (CVE‑2026‑2455) in Mattermost allows attackers to bypass IPv4‑mapped IPv6 address validation.
CVE-2026-2455 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 a… https://www.cve.org/CVERecord?id=CVE-2026-2455
Post summary
The note describes a specific IPv4-mapped IPv6 handling flaw in certain Mattermost versions, with no evidence of PoC, exploit code, or active exploitation.
1 of 1 entries
| Part | Vendor | Product | Version | Target SW | Target HW |
|---|---|---|---|---|---|
| App | mattermost | mattermost_server | - | - | - |