Description
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.
Published: 2026-05-26
Score: 4.3 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-gj84-924c-48fx Algernon: Auto-refresh SSE event server binds to all interfaces by default on Linux/macOS
History

Wed, 27 May 2026 10:30:00 +0000

Type Values Removed Values Added
First Time appeared Xyproto
Xyproto algernon
Vendors & Products Xyproto
Xyproto algernon

Tue, 26 May 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 26 May 2026 17:00:00 +0000

Type Values Removed Values Added
Description 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.
Title Algernon: Auto-refresh SSE event server binds to all interfaces by default on Linux/macOS
Weaknesses CWE-1188
CWE-668
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'}


Subscriptions

Xyproto Algernon
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-26T18:57:12.882Z

Reserved: 2026-05-13T22:18:22.830Z

Link: CVE-2026-46430

cve-icon Vulnrichment

Updated: 2026-05-26T18:57:00.677Z

cve-icon NVD

Status : Deferred

Published: 2026-05-26T17:16:50.943

Modified: 2026-06-17T10:53:40.010

Link: CVE-2026-46430

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-27T10:04:43Z

Weaknesses