GO-2026-5903 Algernon vulnerable to server-side script source disclosure on Windows via NTFS filename in github.com/xyproto/algernon

Algernon vulnerable to server-side script source disclosure on Windows via NTFS filename in github.com/xyproto/algernon...

CVE-2026-52792

creationtimestamp| type| source ---|---|--- 2026-07-02 22:35:07+00:00| published-proof-of-concept| https://github.com/xyproto/algernon/security/advisories/GHSA-mm6c-5j6x-hq8m...

GHSA-MM6C-5J6X-HQ8M Algernon vulnerable to server-side script source disclosure on Windows via NTFS filename

Summary Algernon selects its file handler from filepath.Ext engine/handlers.go:134, which does not treat the NTFS-equivalent names x.lua::$DATA, x.lua., or x.lua as .lua. On Windows, an unauthenticated client appends one of these suffixes to any server-side script on a public path and receives it...

PT-2026-55477

Name of the Vulnerable Software and Affected Versions Algernon version 1.17.8 Description On Windows hosts using the NTFS filesystem, an unauthenticated client can retrieve the raw source code of server-side scripts such as .lua, .tl, .po2, .amber, or .frm located on public paths. This occurs...

GO-2026-5772 Algernon: handler.lua discovery walks parent directories above the server root in github.com/xyproto/algernon

Algernon: handler.lua discovery walks parent directories above the server root in github.com/xyproto/algernon...

GO-2026-5460 Algernon: Host header path traversal in --domain mode reads files and runs Lua from parent dir in github.com/xyproto/algernon

Algernon: Host header path traversal in --domain mode reads files and runs Lua from parent dir in github.com/xyproto/algernon...

GO-2026-5401 Algernon: Auto-refresh SSE event server binds to all interfaces by default on Linux/macOS in github.com/xyproto/algernon

Algernon: Auto-refresh SSE event server binds to all interfaces by default on Linux/macOS in github.com/xyproto/algernon...

GO-2026-5440 Algernon: Auto-refresh SSE event server sets Access-Control-Allow-Origin: * in github.com/xyproto/algernon

Algernon: Auto-refresh SSE event server sets Access-Control-Allow-Origin: in github.com/xyproto/algernon...

GO-2026-5300 Algernon: Auto-refresh SSE event server binds to all interfaces with Access-Control-Allow-Origin: * and no authentication in github.com/xyproto/algernon

Algernon: Auto-refresh SSE event server binds to all interfaces with Access-Control-Allow-Origin: and no authentication in github.com/xyproto/algernon...

GO-2026-5385 Algernon: Single-file mode unconditionally enables debug mode in github.com/xyproto/algernon

Algernon: Single-file mode unconditionally enables debug mode in github.com/xyproto/algernon...

EUVD-2026-31881

Algernon: Host header path traversal in --domain mode reads files and runs Lua from parent dir...

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, and utils.JoinHostPort"", ":5553" resolves to ":5553"...

CVE-2026-46431

Algernon is a small self-contained pure-Go web server. Prior to 1.17.7, the SSE event server's Access-Control-Allow-Origin response header was hardcoded to the wildcard regardless of the caller's Origin. Because EventSource does not preflight and does not send cookies, the wildcard is sufficient ...

CVE-2026-43981

Algernon is a small self-contained pure-Go web server. Prior to 1.17.6, in engine/luahandler.go, the sync.RWMutex protecting LoadCommonFunctions is released before L.Push and L.PCall execute. Since gopher-lua's LState is explicitly not goroutine-safe, concurrent requests race on the shared state...

CVE-2026-43982

Algernon is a small self-contained pure-Go web server. Prior to 1.17.6, uploadedFileSaveIn in lua/upload/upload.go uses filepath.Join with the caller-supplied directory but performs no boundary check after joining. A directory of ../../../tmp resolves cleanly to /tmp, outside the web root. This...

CVE-2026-45721

Algernon is a small self-contained pure-Go web server. Prior to 1.17.7, when Algernon is asked for any URL path that resolves to a directory without an index file, DirPage walks upward through parent directories — past the configured server root — looking for a file named handler.lua to execute a...

CVE-2026-45728

Algernon is a small self-contained pure-Go web server. Prior to 1.17.7, when Algernon is invoked with a single file path instead of a directory, singleFileMode is set to true and debugMode is forcibly enabled. debugMode activates the PrettyError renderer, which on any Lua or template error respon...

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 by joining the configured --dir with the value of the...

Path Traversal

github.com/xyproto/algernon is vulnerable to Path Traversal. The vulnerability is due to DirPage traversing parent directories beyond the configured server root while searching for a handler.lua file, which allows an attacker who can place a malicious handler.lua in an ancestor directory to achie...

Race Condition

Overview github.com/xyproto/algernon/engine is a Affected versions of this package are vulnerable to Race Condition. in the handle process due to the sync.RWMutex being released before L.Push and L.PCall execute. An attacker can cause Lua VM corruption or unpredictable server behavior by making...