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OpenAdvisories
Medium · 4.3 CVE-2026-46430 EUVD-2026-31869GHSA-gj84-924c-48fxGO-2026-5401

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

Published May 26, 2026 · Updated May 26, 2026 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
xyproto algernon < 1.17.7 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260723T184607-160000.1.1 openSUSE-SU-2026:21483-1

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/xyproto/algernon < 1.17.7 1.17.7 GHSA-gj84-924c-48fx

Advisories 1

References