Advisory record · GHSA-xwcr-wm99-g9jc

Algernon: handler.lua discovery walks parent directories above the server root

CVSS 9.0 CriticalCriticalEPSS 0.0044 · 38th percentile

Critical, because:

CVSS score 9.0: 9.0 or more.

Published by the GitHub Advisory Database at 19 May 2026, 14:36 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

Package	Ecosystem	Affected	Fixed in
github.com/xyproto/algernon	Go	<1.17.7	1.17.7

Identifiers: GHSA-xwcr-wm99-g9jc · CVE-2026-45721 · GO-2026-5772
Weakness (CWE): CWE-20 · CWE-426 · CWE-552
Tags: Information disclosure
CWE-20
CWE-426
Published: 19 May 2026
Updated: 25 Jun 2026

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
9.0	Critical	3.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H	CNA (GitHub_M)

CISA KEV Not listed.
EPSS 0.0044, the 38th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 15:06 UTC First seen by agentprime
31 Oct 2026, 15:06 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.