CVE-2026-68548: Algernon: Case-insensitive filesystem lets unauthenticated requests bypass /admin,/repo,/data permission-prefix gate

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 13 Nov 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

0.8%

EPSS score, percentile 55.6 of all scored records. A probability estimated by FIRST, not a report of exploitation.

CISA's SSVC assessment in the CVE record lists exploitation as poc.

How severe?

9.4 Critical

CVSS v3.1 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

No patch or vendor advisory is listed in the CVE record. Check xyproto's advisories.

Which versions are affected?

Affected

• < 1.17.10

Versions by product

Source: CISA KEV 2026.11.13, as of 13 Nov 2026; FIRST EPSS, as of 13 Nov 2026; CVE List, as of 14 Nov 2026. About the data.

Description

Algernon: Case-insensitive filesystem lets unauthenticated requests bypass /admin,/repo,/data permission-prefix gate

Algernon is a small self-contained pure-Go web server. Prior to version 1.17.10, Algernon's URL-prefix authorization gate matches its protected prefixes (/admin, /repo, /data) with case-sensitive strings.HasPrefix, while the exact same raw req.URL.Path is later resolved against the filesystem. On case-insensitive filesystems (Windows NTFS — always; macOS APFS/HFS+ — default), a request for /Admin/secret.lua evades every protected-prefix check, falls through to the public-prefix accept branch, and then resolves on disk to admin/secret.lua. The result is an unauthenticated bypass of the /admin, /repo, and /data authorization boundary, enabling read (and, for Lua files, execution) of protected content. The permission system is active in the default configuration. This issue has been patched in version 1.17.10.

Source: CVE List, as of 14 Nov 2026. About the data.

What to do

Advisories and patches

No patch, vendor advisory or mitigation is listed in the CVE record. Check xyproto's own security advisories for a fix, and compare your version with the affected versions below.

This summary is based on the CVE record as of 14 Nov 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

Source: CVE List, as of 14 Nov 2026. About the data.

Timeline