What is CVE-2026-46430?

CVE-2026-46430 is a medium-severity vulnerability in Xyproto Algernon, classified under Exposure of Resource to Wrong Sphere. CVSS score: 4.3/10. Published 2026-05-26.

How severe is CVE-2026-46430?

Medium severity. CVSS v3 base score is 4.3 out of 10.

RCE in Xyproto Algernon

CVE-2026-46430

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…

EPSS: 0.000 (0.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

Affected products

Xyproto Algernon — versions < 1.17.7

Weakness classification (CWE)

CWE-668 — Exposure of Resource to Wrong Sphere
CWE-1188 — Initialization of a Resource with an Insecure Default

References

security-advisories@github.com (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-46430?: CVE-2026-46430 is a medium-severity vulnerability in Xyproto Algernon, classified under Exposure of Resource to Wrong Sphere. CVSS score: 4.3/10. Published 2026-05-26.
How severe is CVE-2026-46430?: Medium severity. CVSS v3 base score is 4.3 out of 10.