Algernon: Case-insensitive filesystem lets unauthenticated requests bypass /admin,/repo,/data permission-prefix gate
Severity and exploitation
KEV coverage does not rule out exploitation.
Assessment vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:LSeverity
critical9.4CVSS measures technical severity, not the likelihood of an attack.
Known exploitation
Not listed in the checked CISA KEV catalog
Absence from CISA KEV does not rule out attacks.
Public exploit
Exploit reference published
Source-linked evidence; not proof of attacks in the wild or independent validation.
Remediation
Fix status not established
No structured fix or guidance is available here. Check the latest publisher advisory.
What this means
Algernon web server versions prior to 1.17.10 have a case-sensitivity weakness, allowing unauthenticated requests to bypass /admin, /repo, and /data permission checks on case-insensitive filesystems. This enables read and potential execution of protected content. The issue is patched in version 1.17.10.
Summarized by @cf/meta/llama-3.3-70b-instruct-fp8-fast. Verify details against the original sources.Attack conditions
No attack-condition excerpt has been identified here. Review the full source description and references for authentication, network access, and configuration requirements.
Review supporting sources →Affected versions
Check the exact model, release, and any platform requirements against your installation.
xyproto · GitHub_M
algernon
1 range
xyproto · GitHub_M
algernon
Compare with this publisher’s ranges. This does not inspect your installation.
affected
< 1.17.10
Other versions: unknown
What to do
Compare your installed product and version with the affected versions above. A matching product name alone does not confirm exposure.
No structured fix or remediation guidance is available here. Check the full source description and vendor’s latest advisory for a patch or workaround; do not assume another version is safe.
cve.new guidance unless attributed to a publisher. This page does not inspect your installation.
Public exploit evidence
The sources identify public exploit references. We have not independently tested them; their availability does not establish exploitation in the wild.
xyproto/algernon · security/advisories/GHSA-vm84-8c4p-64hx ↗Attributed to CISA-ADPOriginal source description
Read the full publisher description
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.
References
2 sourcesInside the record
Evidence available
Describes the evidence in this view, not whether the product is safe.
Original records
CVE-2026-68548View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.
cve.new JSON →Underlying weaknesses
The source’s classification of what caused the vulnerability.
Contributing organizations · 2
Assigning organization
Additional data publisher
Timeline
All times UTCAdvisory published
Publication date supplied by the source.
Source updated
Latest modification date supplied by the source.
Last imported by cve.new
Latest catalog import, not the date we first saw this advisory.
What changed
Follow changesLarge field values are marked as truncated previews. Original source snapshots remain retained.