CVE-2026-46430 MEDIUM

CVE-2026-46430: Algernon: Auto-refresh SSE event server binds to all interfaces by default on Linux/macOS

Vendor Xyproto
Product algernon
Weakness CWE-668
Published May 26, 2026
Last update May 26, 2026
View on NVD All CVEs

CVSS base score

4.3/10
Attack vector Adjacent
Attack complexity Low
Privileges required None
User interaction None
Confidentiality Low
Integrity None

CVSS vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

What the vulnerability does

01Description

Algernon is a small self-contained pure-Go web server. Prior to 1.17.7, the SSE event server bound to 0.0.0.0:5553 on Linux/macOS by default because the platform-dependent host default in engine/flags.go:39-46 set host = "" for non-Windows, and utils.JoinHostPort("", ":5553") resolves to ":5553". This vulnerability is fixed in 1.17.7.

Key dates

02Disclosure timeline

May 26, 2026 CVE published
May 26, 2026 Record updated