What is CVE-2026-48126?

CVE-2026-48126 is a high-severity vulnerability in Xyproto Algernon, classified under Path Traversal. CVSS score: 8.2/10. Published 2026-05-26.

How severe is CVE-2026-48126?

High severity. CVSS v3 base score is 8.2 out of 10.

Path Traversal in Xyproto Algernon

CVE-2026-48126

Algernon is a small self-contained pure-Go web server. Prior to 1.17.8, when algernon is started with --domain (or --letsencrypt, which silently turns on --domain at engine/flags.go:372), the request handler resolves the served directory b…

Vulnerability class: Path Traversal (Directory Traversal)

EPSS: 0.001 (24.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N.

Affected products

Xyproto Algernon — versions < 1.17.8

Weakness classification (CWE)

CWE-22 — Path Traversal
CWE-23 — Relative Path Traversal
CWE-644 — Improper Neutralization of HTTP Headers for Scripting Syntax

References

security-advisories@github.com (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-48126?: CVE-2026-48126 is a high-severity vulnerability in Xyproto Algernon, classified under Path Traversal. CVSS score: 8.2/10. Published 2026-05-26.
How severe is CVE-2026-48126?: High severity. CVSS v3 base score is 8.2 out of 10.